Dictionary of Dietary Supplement Terms

The ODS Dictionary features terms related to dietary supplements and health found in the ODS fact sheets for consumers.

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26-deoxyactein: A component of black cohosh. It belongs to the family of chemical compounds called triterpene glycosides.
A1C: A blood test that measures the average level of sugar (glucose) in your blood during the past 3 months. An A1C test is used to help diagnose type 2 diabetes. It also shows how well your blood glucose levels have been controlled. Also called a called hemoglobin A1C test.
abetalipoproteinemia: A rare inherited disease in which the intestine cannot absorb fats and fat-soluble vitamins from food. It is associated with fatty stools, diarrhea, nerve problems, and eye disease.
absorption: In nutrition, the process of moving protein, carbohydrates, fats, and other nutrients from the digestive system into the bloodstream. Most absorption occurs in the small intestine.
ACE inhibitor: Angiotensin-converting enzyme inhibitor. A medicine used to treat high blood pressure, stroke, heart attack, diabetes, and kidney problems
acid reflux: A condition in which stomach acid leaks backwards into the esophagus (the muscular tube through which food passes from the throat to the stomach), causing heartburn and irritating the lining of the esophagus.
acne: A sometimes severe skin condition that commonly occurs on the face, neck, back, and chest and includes whiteheads, blackheads, and pimples. Severe acne may be painful and can leave permanent deep scars.
actein: A component of black cohosh. It belongs to the family of chemical compounds called triterpene glycosides.
acute: Sudden, severe, and not long lasting.
additive effect: When the combination of two or more drugs, dietary supplements, or other therapies produces a greater result than one drug, dietary supplement, or therapy given alone. For example, combining valerian with alcohol may have a stronger sedative effect than valerian by itself would produce.
adenoma: A type of tumor that is benign (not cancer).
Adequate Intake: AI. The recommended daily intake of a nutrient estimated by the Institute of Medicine to meet or exceed the amount needed to maintain adequate nutrition for most people in a particular life stage and gender group. An AI is established when not enough information is available from scientific research to determine a Recommended Dietary Allowance (a dietary intake level that is sufficient to meet the nutrient requirements of most people).
administration: The process of giving a person a medicine or dietary supplement by mouth, by vein, on the skin, or by another route. For example, a 14-day administration of valerian extract.
adulterate: To make unsafe or impure by using contaminated or unneeded ingredients; using a strength or quality that is less than claimed; leaving out or substituting key ingredients; or using inferior manufacturing, processing, packaging, or storage procedures.
adverse effect: An unwanted side effect.
adverse event: An unwanted medical problem that occurs during treatment. Adverse events may be unrelated to the treatment or they may be caused by the therapy or procedure. For example, an adverse event may be caused by the toxic effects of a particular drug or dietary supplement or by an interaction with another therapy. Also called adverse effect and side effect.
adverse response: An unwanted or harmful reaction to treatment.
agent: In medicine, a drug, dietary supplement, other substance, or procedure that is used in diagnosing, screening, preventing, or treating a disease.
age-related macular degeneration: AMD. An eye disease that results in a loss of central, "straight-ahead" vision. AMD is the leading cause of vision loss in older Americans.
alcohol dependence: A chronic disease (it lasts a person's lifetime) in which a person is unable to stop drinking once he or she has begun, needs to drink larger amounts of alcohol to get high, and suffers withdrawal symptoms (such as nausea, sweating, shakiness, and anxiety) after stopping drinking. The risk of developing alcohol dependence is influenced by a person's genes and lifestyle. Also called alcoholism.
alcoholic: A person who is not able to stop drinking once he or she has begun, needs to drink larger amounts of alcohol to get high, and suffers withdrawal symptoms (such as nausea, sweating, shakiness, and anxiety) after stopping drinking.
alpha-carotene: A substance found in colorful fruits and vegetables such as pumpkin, carrots, winter squash, and tangerines. It is a carotenoid that can be made into vitamin A by the body.
alpha-tocopherol: The form of vitamin E that is found in the largest amount in humans and is the most active form of vitamin E. It is an antioxidant.
alpha-tocopherol equivalent: A unit of measure used to compare the effects of different forms of vitamin E with the effects of alpha-tocopherol, the most active form of vitamin E.
alpha-tocopherol transfer protein: A substance made in the liver that attaches to vitamin E (alpha-tocopherol), carries vitamin E to the body's tissues, and helps vitamin E stay at a normal level in the body.
alternative medicine: A group of diverse medical and health care systems, practices, and products that are used in place of conventional medicine.
Alzheimer’s disease: A brain disease in which thinking, memory, and reasoning ability is slowly destroyed. In advanced stages, an affected person becomes disoriented and confused, has mood and behavior changes, and has difficulty talking, walking, and swallowing. Alzheimer’s disease is progressive, irreversible, and incurable.
American Academy of Pediatrics: AAP. An organization of pediatricians (medical doctors who specialize in the development, care, and diseases of children) that works to improve the health and well-being of infants, children, adolescents, and young adults.
American Cancer Society: A nationwide, community-based organization involved in cancer research, education, patient services, advocacy, and rehabilitation.
American College of Obstetricians and Gynecologists: A national medical society for obstetricians (doctors who specialize in pregnancy and the delivery of babies) and gynecologists (doctors who specialize in treating diseases of the female reproductive organs).
American National Standards: The American National Standards Institute facilitates the development of the ANS by accrediting the procedures of standards developers. This accreditation signifies that the procedures used by the standards developer in connection with ANS meet the Institute's essential requirements for openness, balance, consensus, and due process.
American National Standards Institute: ANSI is a private, nonprofit organization that coordinates the US voluntary standardization and conformity assessment system. Its mission is to enhance US global competitiveness and the American quality of life by promoting, facilitating, and safeguarding the integrity of the voluntary standardization system. ANSI represents the interests of its company, organizational, government, institutional and international members. ANSI accredits national standards developing organizations and approves American National Standards. It represents US interests in international standards development activities.
amino acid: A chemical building block of protein.
AMRM: The Dietary Supplements Analytical Materials/Reference Materials Program of the Office of Dietary Supplements, National Institutes of Health.
anemia: A condition in which the number of red blood cells in the blood, or the amount of hemoglobin in them, is lower than normal, causing a condition in which red blood cells are not able to supply enough oxygen to all the tissues in the body. Hemoglobin is the substance in red blood cells that carries oxygen to your body's cells.
anencephaly: A condition in which a baby is born without most of a brain and skull. The brain may not be covered by bone or skin. Babies born with this condition do not survive more than a few hours or days. Anencephaly belongs to the group of disorders called neural tube defects.
angina: Chest pain caused by a decrease in the amount of blood flowing into the arteries of the heart. The pain can be severe and crushing and may also be felt in the shoulders, arms, neck, jaw, or back. It is caused by a buildup of plaque in the arteries of the heart, which reduces the supply of blood and oxygen reaching the heart. Physical or emotional stress can trigger angina. The pain usually stops within minutes after the stress ends.
angiotensin receptor blocker: A medication that relaxes and opens up blood vessels. This lowers blood pressure so the heart doesn’t have to work as hard to pump blood.
animal study: A laboratory test using animals to study the development and course of human diseases, and to test the safety and effectiveness of new treatments before they are given to humans.
anorexia: Not feeling hungry or wanting to eat food to an unusual extent.
anthocyanins: A group of pigments that naturally occur in some plants and produce the pink, red, and violet colors of fruits, leaves, and flowers. Berries, cherries, red wine, eggplant, red cabbage, and red and purple grapes are sources of anthocyanins.
antibiotic: A drug used to treat infections caused by bacteria and other microorganisms.
antibody: A type of protein made by white blood cells in response to an antigen (a foreign substance in the body). Each antibody binds to only one specific antigen and helps to destroy it. An antibody can work in several ways, depending on the nature of the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigens.
anticoagulant: A drug or other substance that stops blood clots from forming. Also called a blood thinner.
anticonvulsant: A drug that prevents, reduces, or stops convulsions or seizures.
antiestrogen: A substance that blocks the effects of estrogens (a family of hormones that helps develop and maintain female sex characteristics and the growth of long bones).
antioxidant: A substance that protects cells from damage caused by free radicals (compounds formed during the metabolism of oxygen). It may help prevent the development of some chronic diseases such as cancer. Antioxidants include beta-carotene; lutein; lycopene; vitamins A, C, and E; selenium; and zinc.
AOAC International: AOAC International is a not-for-profit voluntary consensus standards body cited in the US Code of Federal Regulations under Title 21: "It is the policy of FDA in its enforcement program to use methods of analysis of AOAC International when available and applicable." AOAC is also cited under Title 9 within this context by the USDA. AOAC was founded in 1884 as the Association of Official Agricultural Chemists; in 1965 the Association's name changed to the Association of Official Analytical Chemists to reflect expansion of scope. The organization now refers to itself as AOAC International.
AOAC Official Methods of Analysis^SM: These methods are recognized worldwide as an authoritative resource because of thorough and rigorous testing characterization. The methods are written into the US Code of Federal Regulations, product specifications and product acceptance; relied on in legal proceedings; and required as a basis of national and international trade. They are adopted by other national and international standards organizations. They can be used with confidence by regulatory agencies, regulated industries, product testing laboratories, and academic institutions to determine compliance with government regulations, to maintain quality control and process requirements, to set and evaluate compliance with terms of procurement contracts, to conduct national and international trade, and to support research.
AOAC Official Methods of Analysis^SM Program: This program of AOAC International is designed to provide methods of analysis for which performance characteristics have been determined and tested.
apathy: Having no emotion, interests, or concerns.
aqueous: Having to do with water.
arrhythmia: An irregular heartbeat that can make you feel faint or dizzy because your heart is not pumping enough blood through your body. Arrhythmia is treatable but if not treated it can damage your heart, brain, and other organs and can lead to stroke or heart attack.
arthritis: A group of diseases in which one or more joints (places in the body where two bones connect) become swollen and painful. The most common type of arthritis is osteoarthritis. It is caused by the breakdown of cartilage, a type of tissue that cushions and supports the joint. Without cartilage, the bones in the joint rub together, causing inflammation (swelling, redness, pain, and warmth) and stiffness. Arthritis may affect the fingers, hips, knees, lower back, feet, or any joint in the body.
association: A relationship between two conditions or states such that if one is present, the other is likely to be present as well. An association between two conditions or states, however, does not necessarily imply a cause and effect relationship. The terms association and relationship are often used interchangeably.
asthma: A long-lasting disease in which the airways that carry air in and out of the lungs sometimes become narrower, limiting the amount of air that can flow through them, and causing wheezing, coughing, chest tightness, and trouble breathing (called a spasm). Cells in the airways may also make more mucus than usual, which narrows the airways even more. Asthma can also cause death, but can usually be controlled with regular treatment. It may be caused by allergies (such as to pet hair, dust, mold, pollen, or cockroaches), respiratory infections, vigorous exercise, environmental factors (such as cigarette smoke, certain foods, or pollution), stress, and genetics (a child is more likely to have asthma if one or both parents have asthma).
ataxia: Loss of muscle coordination.
atherosclerosis: A condition in which certain blood vessels (arteries) are clogged and have hardened. Atherosclerosis is caused by fat and cholesterol deposits (plaque) that block blood flow to certain parts of the body. It increases a person's chance (risk) of having a heart attack, stroke, kidney damage, or other diseases involving the arteries.
atrophic gastritis: A long-lasting (chronic) condition in which the linining of the stomach is inflamed. Gradually the lining wastes away, destroying the glands that make stomach acid.
atrophy: A weakening, decrease in size, or wasting away of a tissue, organ, or part of the body. For example, the muscles of a leg that has been in a cast for some time will atrophy because they are not being used, causing them to become smaller and weaker.
attention deficit hyperactivity disorder: ADHD. A common mental disorder that usually develops before age 7 and may continue into adulthood. Symptoms include inattention, excessive impulsiveness, and/or inability to remain still and quiet.
autoimmune disease: A condition in which the body recognizes its own tissues as foreign and directs an immune response against them.
Ayurvedic: A system of medicine that originated in India several thousand years ago. Complex herbal-mineral combinations play key roles in Ayurvedic medicine, and other approaches such as diet and lifestyle modifications are also used. Also called Ayurveda.
B vitamin: A nutrient that is important for cell function. The B vitamins are biotin, folate, niacin, pantothenic acid, riboflavin (vitamin B₂), thiamin, vitamin B₆, and vitamin B₁₂. The B vitamins make up the vitamin B complex.
bacteria: Single-celled organisms that are too small to be seen without a microscope. Bacteria are found everywhere and may be helpful or harmful.
barbiturate: A category of drug used to treat seizure disorders, insomnia, and anxiety and to calm patients before surgery. It belongs to the family of drugs called central nervous system depressants.
bariatric surgery: An operation on the stomach and/or intestines to help patients with extreme obesity lose weight. Some types of bariatric surgery limit the amount of food your stomach can hold. Other types of surgery change how food is digested, which stops some calories (and nutrients, such as vitamins) from being absorbed.
benzodiazepine: A category of drug used to treat seizure disorders, insomnia, anxiety, alcohol withdrawal, and muscle spasms, and to calm patients before surgery. It belongs to the family of drugs called central nervous system depressants.
beriberi: A condition that occurs in people who are deficient in thiamine (vitamin B1). There are two types of beriberi: wet and dry. Wet beriberi affects the cardiovascular system and can cause increased heart rate, shortness of breath, and swelling of the lower legs. Dry beriberi affects the nervous system and can cause difficulty walking, loss of feeling in the hands and feet, paralysis of the lower legs, mental confusion, speech difficulty, pain, and vomiting. This condition is rare in the United States. Alcohol abuse increases the risk of developing beriberi.
beta-carotene: A carotenoid found in carrots, cantaloupe, apricots, sweet potatoes, pumpkin, winter squash, mangos, collard greens, spinach, kale, broccoli, and other orange, red, and dark green fruits and vegetables.
beta-cryptoxanthin: A substance found in citrus fruit, peaches, and apricots. It is an antioxidant. Beta-cryptoxanthin is one of a group of carotenoids that can be made into vitamin A in the body.
bias: In a clinical trial, the result of a flaw in the study design or method of collecting or interpreting the study information that can lead to incorrect conclusions.
bile acid sequestrant: A type of medication that is used to treat high cholesterol.
binder: An inactive ingredient (one that has no medicinal effect on the body, such as starch, salt, or sugar) used to hold together the contents of a pill or tablet.
bioavailability: The amount of a nutrient that reaches the body's tissues after it is eaten.
biologic product: A substance made from biological (living) sources and used to prevent, treat, or cure disease or injury. Examples include antibodies, vaccines, and blood products.
biological activity: An effect on life processes. For example, the biological activity of a vitamin means the effect it has on specific life processes in the body.
biotin: A nutrient that is needed by the body to change carbohydrates, fats, and amino acids into energy and the basic materials needed for important life processes. It belongs to the group of vitamins called the vitamin B complex. Biotin is found in some foods, including egg yolk, liver, and yeast.
biotinidase deficiency: An inherited condition in which the body cannot use the biotin (a B vitamin) in foods . The body needs biotin to help break down food into energy. Symptoms of this condition typically appear in infancy or childhood. Kids with mild biotinidase deficiency may have weak muscles, skin rashes, and hair loss. Severe biotinidase deficiency can cause seizures, breathing problems, hearing and vision loss, problems with movement and balance, and an infection called candidiasis. Affected children also grow and develop more slowly. Biotinidase deficiency can be treated by a healthcare provider with high doses of biotin.
black cohosh: A plant whose rhizome and root are used to relieve hot flashes and other symptoms of menopause. It is not known how black cohosh works or whether it acts like estrogen (a hormone needed to develop and maintain female sex characteristics and the growth of long bones). Historically, black cohosh has been used to treat many medical conditions. Also called black snakeroot, bugbane, bugwort, rattleroot, rattletop, rattleweed, and macrotys. Latin names: Actaea racemosa and Cimicifuga racemosa.
bladder cancer: Uncontrolled growth of abnormal cells in the bladder (the organ that stores urine).
blinding: A process used in clinical trials to assign individuals to the control group (to receive the standard treatment) or the test group (to receive the new treatment under study) without the individuals or the researchers knowing to which group they have been assigned. Blinding helps ensure that information collected in the study is true and not biased (flawed). In a single-blinded study, the individuals do not know whether the standard treatment or a new treatment is being given. In a double-blinded study, neither the individuals nor the researchers know which treatment is being given.
blood sugar: The main source of energy used by the body's cells. Blood sugar comes from food and is made by the liver, and is carried to the cells through the bloodstream. Also called blood glucose.
blood vessel: A tube through which blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.
blood-brain barrier: A network of specialized cells that prevents certain substances, including many toxins and potentially harmful substances, from leaving the blood vessels and entering the brain.
blue cohosh: A plant that has been used to treat menstrual disorders and to start labor. It may be unsafe and should not be confused with black cohosh. Latin name: Caullophylum thalictroides.
body stores: The amount of a nutrient that stays in the body after eating and is available for future use. The size and location of this extra supply differs depending on the nutrient. For example, iron is stored in the liver.
bone density: A measurement of bone mass and an indicator of bone strength and health. Also called bone mineral density.
bone marrow: The soft, sponge-like tissue in the center of most bones. It produces white blood cells, red blood cells, and platelets.
botanical: Having to do with plants or plant parts, or dietary supplement products made from plants.
botanist: A scientist who studies the biology of plants.
breast cancer: Uncontrolled growth of abnormal cells in the breast.
BRT: Botanical Review Team of the Center for Drug Evaluation Research of the US Food and Drug Administration (FDA). BRT provides scientific expertise on botanical issues to CDER's reviewing staff and ensures consistent interpretation of FDA's "Guidance for Industry: Botanical Drug Products."
caffeic acid: A component of black cohosh.
calcium: A mineral found throughout the body. Calcium is needed for healthy bones and teeth, for nerves and enzymes to function properly, and for blood clotting. Calcium is found in some foods, including milk, yogurt, and cheese, and in Chinese cabbage, kale, broccoli and fortified foods, such as many drinks, tofu, and cereals.
calcium carbonate: A chemical compound naturally found in chalk, some seashells and other substances. Calcium carbonate is used in antacid drugs to treat indigestion and as a source of calcium to supplement the diet.
cancer: A group of diseases in which cells divide abnormally and without control, and spread to nearby tissues and other parts of the body. Without treatment, cancer can stop organs from working normally, damage body systems, and cause the patient to die. Cancer may be caused by multiple factors, such as radiation, sunlight, tobacco, certain viruses, and poisonous chemicals; however, the cause of many cancers is unknown.
cancer survivor: A person with cancer, from the time he or she is diagnosed through the balance of his or her life.
capsule: A gelatin shell containing a dose of medicine, a vitamin, or other dietary supplement.
carcinogen: A substance that causes cancer.
cardiac: Having to do with the heart.
cardiac arrest: A condition in which the heart suddenly stops beating.
cardiovascular disease: CVD. A general term referring to disorders of the heart and blood vessels. CVD includes coronary artery disease, heart failure, atherosclerosis, high blood pressure, peripheral artery disease, and stroke.
cardiovascular event: A heart attack, stroke, or other occurrence that damages the heart or blood vessels.
cardiovascular system: The heart, blood, and blood vessels.
carotenoids: A group of pigments that naturally occur in some plants, algae, and bacteria. They are responsible for the yellow, orange, and red colors in plant foods, such as carrots, red peppers, pumpkin, beets, and sweet potatoes. Carotenoids are also found in spinach, collards, kale, mustard greens, and other dark green leafy vegetables. Common carotenoids include alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin..
case report: A detailed record of the diagnosis, treatment, and follow-up of an individual patient. Case reports also contain some information about the patient (such as age, gender, and ethnic origin).
cataract: A condition in which the lens of the eye becomes cloudy. Symptoms include blurred, cloudy, or double vision; sensitivity to light; and difficulty seeing at night. Without treatment, cataracts can cause blindness. Cataracts occur in people of all ages but are most common in the elderly.
celiac disease: An autoimmune disorder in which eating gluten (a protein found in wheat, rye, barley, and possibly oats) causes the immune system to damage the small intestine, making it unable to absorb nutrients. It is a genetic disease that sometimes becomes active for the first time after surgery, pregnancy, childbirth, viral infection, or extreme stress. Also called sprue.
cell: The individual unit that makes up the tissues of the body. All living things are made up of one or more cells, which are the smallest units of living structure capable of independent existence.
cell differentiation: The process during which young, immature (unspecialized) cells take on individual characteristics and reach their mature (specialized) form and function. For example, unspecialized cells differentiate to become nerve cells, muscle cells, blood cells, or other specialized tissue cells.
cell division: The method by which a single cell divides to create two cells. This is a continuous process that allows a population of cells to increase in number or remain the same in number.
cell line: Cells of a single type that have been adapted to grow and divide in the laboratory and are used in research.
cell membrane: An envelope that contains the contents of a cell and controls what passes into and out of the cell.
cell study: A research tool in which individual units (cells) that make up the tissues of an animal or human body are studied outside of the body to find out if a drug or other treatment is likely to be safe and useful in the body. Cell studies are usually completed before testing is done in humans.
Center for Food Safety and Applied Nutrition: CFSAN, US Food and Drug Administration, Department of Health and Human Services. CFSAN is responsible for developing policy and regulations for dietary supplements.
Centers for Disease Control and Prevention: CDC. An organization within the federal government responsible for prevention and control of infectious disease and other health threats. It is part of the US Department of Health and Human Services.
central nervous system depressant: A medication that changes brain function and causes drowsiness. It may be used in anesthesia. Also called CNS depressant.
central nervous system disorder: A disease or condition that affects the brain, the spinal cord, and the ability to think, move, see, hear, taste, smell, or touch.
certified reference material: A reference material characterized by a metrologically valid procedure for one or more specified properties, accompanied by a certificate that provides the value of the specified property, its associated uncertainty, and a statement of metrological traceability. Certified reference materials are traceable to international standards with a known uncertainty and therefore can be used to address all aspects of bias (method, laboratory, and within-laboratory) simultaneously, assuming that there is no matrix mismatch.
chamomile: The flower of this herb is used in some cultures for its calming effect, to promote sleep, and as a treatment for indigestion. It is being studied in relieving chronic pain in children with bowel disorders. Latin names: Matricaria recutita and Anthemis nobilis.
Chemical Science and Technology Laboratory: CSTL, National Institute of Standards and Technology, Department of Commerce. CSTL supports the food and dietary supplement industry by providing reference measurements and reference standards for quality assurance and to help ensure compliance with nutritional labeling regulations.
chemoprevention: The use of drugs, vitamins, or other substances to try to reduce the risk of, or delay the development or recurrence of, cancer.
chemotherapy: A chemical that kills bacteria, viruses, fungi, or tumor cells. It usually refers to drugs used in cancer treatment.
cholesterol: A substance found throughout the body. It is made by the liver and is an important component of cells. Cholesterol is also used to make hormones, bile acid, and vitamin D. Foods that come from animals contain cholesterol, including eggs, dairy products, meat, poultry and fish. High blood levels of cholesterol increase a person's chance (risk) of developing atherosclerosis and heart disease.
chronic: Happening for a long time, persistently, or repeatedly.
chronic disease: A condition that is continuous or recurrent, is not easily cured, and cannot be passed from person to person. Examples of chronic diseases include heart disease, diabetes, and asthma.
cimicifugin: A resin (a component of some plants) found in black cohosh.
cimicifugoside: A component of black cohosh. It belongs to the family of chemical compounds called triterpene glycosides.
cirrhosis: A condition in which damaged liver cells are replaced with scar tissue, making it progressively more difficult for the liver to function properly.
clarity: Clearness.
clinical significance: In medicine, a judgment that a change caused by a treatment or dietary supplement has practical importance for a patient's health. Clinical significance is different from statistical significance, which focuses on making a mathematical determination about whether the change might or might not be expected to happen by chance. Example: Suppose the results of a clinical trial show that people with sleep disorders who took a particular supplement slept 10 minutes longer each night than people who took a placebo and the difference of 10 minutes was statistically significant. Also, the results of earlier research show that sleeping at least 60 minutes longer each night would help a person with a sleep disorder feel well rested when they wake up. The results of this study would not be judged as clinically significant because the people who took the supplement only slept an additional 10 minutes and not the 60 minutes experts have determined can help a person with a sleep disorder feel well rested when they wake up. But the study results would still be considered statistically significant.
clinical trial: A type of research study that uses volunteers to test the safety and efficacy (the ability to produce a beneficial effect) of new methods of screening (checking for disease when there are no symptoms), prevention, diagnosis, or treatment of a disease. Also called a clinical study.
cobalamin: A group of chemical compounds that works as vitamin B₁₂ in the body. Cobalamin is required to maintain healthy nerve cells and produce normal red blood cells. It is involved in making DNA (the genetic material in all cells), and in the metabolizing of foods containing carbohydrate, fat, or protein. Cobalamin is found in foods that come from animals and in fortified breakfast cereals. Also called vitamin B₁₂.
cobalt: An organic substance found in the earth and needed in very small amounts. It is also a necessary component of vitamin B₁₂. A cobalt deficiency leads to anemia; too much cobalt can lead to a greater than normal number of red blood cells.
cognition: The intellectual and mental ability to be aware, think, learn, imagine, remember, reason, have perceptions, and make judgments.
cognitive function: Mental awareness and judgment.
cognitive skills: Mental and intellectual capabilities such as language, reading, math, reasoning, and critical thinking.
collagen: A strong, flexible protein found in cartilage, tendons, bone, skin, and other connective tissue.
colon: A tube-like organ about 5 feet long in adults that is connected to the small intestine at one end and the anus at the other. The colon absorbs water, some nutrients, and electrolytes (such as sodium and chloride) from partially digested food. The remaining material (solid waste called stool) moves through the colon to the rectum and leaves the body through the anus as a bowel movement. The colon is part of the digestive system (a series of organs from the mouth to the anus). Also called the large intestine.
colon cancer: Uncontrolled growth of abnormal cells in the large intestine (the tube-like organ connected to the small intestine at one end and the anus at the other).
colorectal cancer: Uncontrolled growth of abnormal cells in the colon (the longest part of the large intestine) and/or the rectum (the last several inches of the large intestine before the anus).
columnar cell: A type of cell that lines the internal and external surfaces of the body.
commercial preparation: A product such as a drug or dietary supplement made in large quantities to be sold.
common cold: A nose and throat infection caused by a virus. Symptoms include runny nose, sneezing, congestion, sore throat, and cough.
complaint: In medicine, a disorder, disease, or symptom.
complementary and alternative medicine: A group of diverse medical and health care systems, practices, and products that are not presently considered to be part of conventional medicine.
complementary medicine: A group of diverse medical and health care systems, practices, and products that are used together with conventional medicine.
complication: In medicine, an illness or condition that occurs while a patient has a disease. The complication is not a part of the disease, but may be a result of the disease or may be unrelated.
compound: In pharmacy, a substance that contains more than one ingredient.
conception: In biology, the fertilization of an egg by a sperm that begins a pregnancy.
congenital: A mental or physical condition that a baby is born with. It may be hereditary (passed from parent to child through information in the genes), or it may occur while the fetus is developing in the womb, or it may be a combination of both.
conjugated estrogen: A type of female hormone that is made from the urine of pregnant horses or from plants. It is used in estrogen replacement therapy, and to treat the symptoms of menopause, osteoporosis in women who have been through menopause, advanced breast cancer, and some types of advanced prostate cancer.
connective tissue: Cells that work together to protect and support the body’s muscles, joints, organs, skin, and other tissues. Examples of connective tissue include cartilage, fat, blood, and bone.
consensus: A general agreement.
constipation: A condition in which stool becomes hard, dry, and difficult to pass and bowel movements happen infrequently. Other symptoms may include painful bowel movements and feeling bloated, uncomfortable, and sluggish.
constituent: A component, part, or ingredient of a larger whole. For example, valerenic acid and valepotriate are constituents of the dietary supplement valerian.
consume: To eat or drink.
Continuing Survey of Food Intakes by Individuals: CSFII. A nationwide survey conducted by the US Department of Agriculture that collects information about the kinds and amounts of foods Americans eat. The information is used to study the nation's food supply, including learning whether the foods available to consumers contain enough of the nutrients needed to maintain a healthy diet, finding out how much the foods provided by food assistance programs (such as Food Stamps) contribute to a person's nutrition needs, and calculating the amount of a pesticide that can be used on a crop while providing a safe food product. In 2002, CSFII was incorporated into the ongoing National Health and Nutrition Examination Survey.
control: In a clinical trial, the group of participants that does not receive the new treatment being studied. This group is compared with the group receiving the new treatment, to see whether the new treatment works. In an observational study, the controls are participants who do not have a particular health condition; the control group is compared with the group of participants who do have the condition to see if certain factors (such as diet, activity level, or use of dietary supplements) may be associated with developing or preventing the condition.
control group: In a research study or clinical trial, the group that does not receive the new treatment being studied. This group is compared with the group that receives the new treatment, to see whether the new treatment works.
conventional drug: A currently accepted and widely used medicine for a certain type of disease, based on the results of past clinical research.
conventional food: Edible substances, excluding organic food, genetically modified food, functional food, and dietary supplements.
copper: In nutrition, a mineral the body needs (along with iron) to make red blood cells. Copper also helps keep the immune system, blood vessels, nerves, and bones healthy. Copper is found in some foods, including oysters and other shellfish, whole grains, beans, nuts, potatoes, organ meats, dark leafy greens, and dried fruits.
cornea: The clear dome-shaped surface covering the front of the eye.
cornification: The changing of cells that line the internal and external surfaces of the body into an outer layer of flat cells that look like fish scales under a microscope). Also called keritinization.
coronary artery: A blood vessel that supplies blood and oxygen to the heart.
coronary heart disease: A disease in which the blood vessels (coronary arteries) that carry blood and oxygen to the heart are narrowed or blocked, which can cause chest pain, shortness of breath, and heart attack. It is usually caused by a build-up of fat and cholesterol deposits inside the arteries (atherosclerosis).
Crohn's disease: A long-lasting (chronic) disease that causes severe irritation in the gastrointestinal tract. It usually affects the lower small intestine (called the ileum) or the colon, but it can affect any part of the digestive tract from the mouth to the anus. It is painful, causing severe watery or bloody diarrhea, and may lead to life-threatening complications. Crohn's disease is a form of inflammatory bowel disease.
cruciferous vegetable: A type of vegetable including arugula, bok choy, broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, kohlrabi, mustard greens, radishes, rutabaga, turnips and watercress.
cure: To heal or restore health; a treatment to restore health.
cystic fibrosis: A common inherited disease that causes the body to make thick, sticky mucus that builds up in the lungs and blocks the airways, leading to repeated serious lung infections. Mucus also blocks the pancreas, which stops digestive enzymes from reaching the intestines. Cystic fibrosis also causes very salty sweat, which can lead to dehydration, increased heart rate, tiredness, low blood pressure, and heat stroke.
cytology: The study of cells using a microscope (a device that uses a combination of lenses to make enlarged images of tiny objects).
cytotoxic: Cell-killing.
Daily Value: DV. A term used on a food or dietary supplement label that tells you how much of a particular nutrient (such as calcium) one serving of the food or supplement provides. DVs are given as percentages and help you compare one product with another. For example, a food that lists 40% DV for calcium would provide much more calcium than another food that lists 10% DV for calcium. For each nutrient, there is one DV for all people aged 4 years and older. DVs are established by the U.S. Food and Drug Administration.
dairy food: Milk and products made with milk, such as buttermilk, yogurt, cheese, cottage cheese, and ice cream.
data: Facts and information.
day 0: Sometimes used to indicate the first day of treatment.
deciliter: dL. A unit of volume in the metric system equal to one-tenth of a liter (about two-tenths of a pint).
decoction: A substance made by simmering some types of roots, bark, and berries in water to extract their desired ingredients. It is simmered for a longer time than that needed to make tea and may be drunk hot or cold.
deficiency: An amount that is not enough; a shortage.
degeneration: A condition in which tissues in the body lose their ability to function properly.
delayed development: Failure of a child to reach physical or behavioral milestones (such as rolling over, crawling, walking, and talking) at expected ages.
dementia: Damaged brain function (thinking, learning, making decisions, remembering) that worsens over time. It disrupts activities of daily living such as bathing, dressing, and walking.
deoxyribonucleic acid: DNA. The molecules inside cells that carry genetic information and pass it from one generation to the next.
depression: A serious medical condition that can interfere with an individual's ability to work, study, sleep, and eat. Symptoms include ongoing feelings of sadness and despair, loss of energy, and loss of interest or pleasure in activities that were once enjoyed. A person who has depression may experience changes in eating or sleeping habits, and have thoughts of death or suicide.
derivative: In chemistry, a compound made from or related to another compound.
diabetes: A disease in which blood sugar (glucose) levels are high because the body is unable to use glucose properly. Diabetes occurs when the body does not make enough insulin, which helps the cells use glucose, or when the body no longer responds to insulin.
diagnose: The process of using signs and symptoms to identify a disease.
dialysis: The process of filtering the blood when the kidneys are not able to cleanse it.
diarrhea: Loose, watery stools.
diarrheal infection: A disease in which viruses, bacteria, or parasites invade the body and multiply, causing abdominal pain, cramping, and frequent watery bowel movements.
diazepam: A drug that is used as a sedative and muscle relaxant, and to treat anxiety and epileptic seizures.
dietary fiber: A substance in plants that you cannot digest. It adds bulk to your diet to make you feel full, helps prevent constipation, and may help lower the risk of heart disease and diabetes. Good sources of dietary fiber include whole grains (such as brown rice, oats, quinoa, bulgur, and popcorn), legumes (such as black beans, garbanzo beans, split peas, and lentils), nuts, seeds, fruit, and vegetables.
Dietary Folate Equivalent: DFE. A term used to describe the Recommended Dietary Allowance of folate. DFE accounts for the easier absorption of folic acid in supplements and fortified foods compared with folate found naturally in foods, which is absorbed only about half as well. One DFE = 1 microgram (mcg) food folate = 0.6 mcg folic acid from supplements and fortified foods.
Dietary Guidelines for Americans: Advice from the federal government to promote health and reduce the chance (risk) of long-lasting (chronic) diseases through nutrition and physical activity. The Guidelines are updated and published every 5 years by the US Department of Health and Human Services and the US Department of Agriculture.
Dietary Reference Intake: DRI. A term developed by the Institute of Medicine that refers to a set of recommendations used to plan and evaluate the nutrient intake of healthy people. The DRIs include the Estimated Average Requirement (an intake value estimated to meet the nutrient requirements of half of all people), the Recommended Dietary Allowance (a dietary intake level that is sufficient to meet the nutrient requirements of most people), Adequate Intake (a recommended nutrient intake that meets or exceeds the amount needed to maintain adequate nutrition in most people), and the Tolerable Upper Intake Level (the largest daily intake of a nutrient that is considered unlikely to cause harmful side effects for most people).
dietary supplement: A product that is intended to supplement the diet. A dietary supplement contains one or more dietary ingredients (including vitamins, minerals, herbs or other botanicals, amino acids, and other substances) or their components; is intended to be taken by mouth as a pill, capsule, tablet, or liquid; and is identified on the front label of the product as being a dietary supplement.
digestion: The process the body uses to break down food into simple substances for energy, growth, and cell repair.
digestive disorder: An abnormal condition affecting any part of the digestive tract (mouth, esophagus, stomach, small and large intestines, rectum and anus) or organs involved in digestion (such as the stomach, liver, pancreas, or gallbladder). Also called digestive disease.
digestive tract: The large, muscular tube that extends from the mouth to the anus, in which hormones, enzymes, and the movement of muscles work together to digest food. Also called the gastrointestinal (GI) tract.
disability: A physical or mental impairment that significantly limits a person's ability to walk, see, hear, speak, breathe, learn, work, or take care of oneself.
disease progression: The way a medical condition develops over time.
disorder: In medicine, a disturbance of normal functioning of the mind or body. Disorders may be caused by genetic factors, disease, or trauma.
disorientation: A mental state marked by confusion about time, place, or who one is.
distal ileum: The end of the small intestine that attaches to the large intestine.
distress: Mental or physical pain or suffering.
diuretic: A drug or other substance that increases the amount of urine made by the body.
dose: The amount of medicine or other substance taken at one time or over a specific period of time.
double-blind: Describes a clinical trial in which neither the researcher nor the patient knows which of several possible therapies the patient is receiving.
drug: Any substance (other than food) that is used to prevent, diagnose, treat, or relieve symptoms of a disease or abnormal condition. Also, a substance that alters mood or body function or that can be habit-forming or addictive, especially a narcotic.
duration: The length of time that something lasts.
echinacea: A plant that is native to North America. Traditionally, it has been used for colds, flu, and other infections.
edema: Swelling caused by excess fluid in the body. Edema often affects the hands, arms, feet, ankles, legs, hands, and arms.
effectiveness: In medicine, the ability of an intervention (for example, a drug, surgery, or a dietary supplement) to produce the desired beneficial effect under the usual conditions of care by a health care provider.
efficacy: In medicine, the ability of an intervention (for example, a drug, surgery, or dietary supplement) to produce the desired beneficial effect under the best possible conditions of care, such as a clinical trial.
electrolyte: In the body, a dissolved mineral (such as sodium, potassium, chloride, or calcium) that helps control the amount of water in the blood, inside the cells, and in the spaces between the cells, and helps control the way cells work (such as moving nutrients into cells and moving wastes out of cells).
endocrine system: Hormone-producing glands that affect growth and development, hunger, metabolism (chemical changes in the body), sleep, sexual function, and mood. The endocrine system includes the thyroid gland, pituitary gland, adrenal gland, parathyroid glands, adrenal glands, pancreas, ovaries, and testicles.
endometrium: A layer of tissue that lines the uterus.
endpoint: A specific outcome measured in a clinical trial that is used to judge how well the treatment works (treatment efficacy). For example, the endpoint measured in a clinical trial may be weight loss, quality of life, or survival.
enriched: When certain nutrients (such as vitamins and minerals) have been added to a food product to replace nutrients that may be lost during processing or storage. For example, white flour is enriched with thiamin, riboflavin, niacin, and iron because those nutrients are lost when grain is made into flour. Folic acid is also added to enriched flour.
enzyme: A protein that speeds up chemical reactions in the body.
eosinophil: A type of white blood cell.
epidemiologic study: Research that examines the patterns, causes, and control of a disease in a population of people.
epilepsy: A group of disorders that sometimes disrupts proper communication between brain cells, causing a seizure (a sudden change in behavior due to excessive electrical activity in the brain). It usually occurs in young children and the elderly. Epilepsy can be caused by abnormal brain development, brain damage, illness, tumors, or strokes. Often the cause is not known.
epithelium: A thin layer of tissue that covers organs, glands, and other structures within the body.
ER-negative: Estrogen receptor negative (ER-). Having to do with breast cancer cells that do not have a protein (a receptor molecule) to which estrogen will attach. Breast cancer cells that are ER- do not need the hormone estrogen to grow and usually do not respond to hormone (antiestrogen) therapy that blocks these receptor sites.
ER-positive: Estrogen receptor positive (ER+). Having to do with breast cancer cells that have a protein (a receptor molecule) to which estrogen will attach. Breast cancer cells that are ER+ need the hormone estrogen to grow and will usually respond to hormone (antiestrogen) therapy that blocks these receptor sites.
esophageal cancer: Uncontrolled growth of abnormal cells in the esophagus (the hollow muscular tube that moves food and liquid from the throat to the stomach). Cancer starts in the mucous membrane lining the inside of the esophagus and spreads outward through the layers of connective tissue and muscle as it grows.
esophagus: The muscular tube through which food passes from the throat to the stomach.
essential: In nutrition, essential nutrients are ones that we must consume for good health because our bodies cannot make them. Essential nutrients include vitamins and minerals.
esteem: Admiration, regard, respect, and value.
ester: A chemical compound made by the reaction between an alcohol and an acid.
Estimated Average Requirement: EAR. A daily dietary intake value estimated by the Institute of Medicine to meet the nutrient requirements of half of all healthy people in a particular life stage and gender group. It is used to calculate the Recommended Dietary Allowance (that amount of a nutrient that meets the nutrient requirements of nearly all healthy individuals).
estradiol: A form of the hormone estrogen.
estriol: A form of the hormone estrogen.
estrogen: A hormone (a chemical made by the body that controls the actions of certain cells or organs) that is needed to develop and maintain female sex characteristics and the growth of long bones. Estrogens are also made in the laboratory and are used in birth control and to treat symptoms of menopause, menstrual disorders, and osteoporosis.
estrogen receptor binding assay: ER binding assay. A laboratory test to determine the presence of a protein found on cells of female reproductive tissue, some other tissues in the body, and some cancer cells. The hormone estrogen will attach (bind) to the receptors inside the cells and may cause the cells to grow.
ethanol: A type of alcohol. Also called ethyl alcohol or grain alcohol.
evidence: Information used to support the use of a particular screening procedure, treatment, or preventive measure. In medicine, evidence needed to determine effectiveness is provided by laboratory research, clinical trials, and other studies.
excitatory neurotransmitter: A chemical that increases the number of messages sent between nerve cells (neurons). For example, acetylcholine is an excitatory neurotransmitter that is involved in wakefulness, attentiveness, anger, aggression, muscle contraction, release of hormones, and other actions.
expert opinion: In medicine, the judgment of a respected healthcare professional, based on clinical experience or reports of expert committees. Expert opinions are important when results of controlled clinical trials and other scientific studies are not available to provide health care recommendations.
extended-release: In medicine, pills and capsules that release a drug in the body slowly over time.
extract: A substance made by soaking an herb in a liquid that removes specific types of chemicals. The liquid can be used as is or evaporated to make a concentrate or a dry extract for use in capsules or tablets.
failure to thrive: A condition in which infants and children are dramatically smaller or shorter than other children of the same age and gender, and physical, mental, and social skills are significantly delayed. Causes include medical disorders, environmental factors, malnutrition, and neglect.
fat soluble: Able to be dissolved in fat.
fatal: Deadly; causing death.
fatigue: Extreme tiredness and an inability to function due to lack of energy.
Federal Trade Commission: FTC. A federal agency that protects consumers by preventing deceptive and unfair business practices. This includes unfair or deceptive advertising and marketing practices.
fetal: Having to do with a fetus (the developing human from 7 to 8 weeks after conception until birth).
fetus: The developing human from 7 to 8 weeks after conception until birth.
fibrocystic breast disease: A common condition in which the breasts feel bumpy, tender, and painful, especially before a menstrual period.
filler: An inactive ingredient (one that has no medicinal effect on the body, such as lactose or starch) that is used to provide consistency and uniformity in the size and weight of a pill or tablet.
flavanols: Substances that naturally occur in some plants such as tea, cocoa, red grapes, berries, apples, and red wine. Also called flavan-3-ols.
flavanones: Substances that naturally occur in some plants, especially citrus.
flavonoids: Substances that naturally occur in many plants. Green tea, cocoa, coffee, red wine, berries, apples, citrus fruit, and cruciferous and colorful vegetables contain significant amounts of flavonoids. Plant foods contain more than 6,000 flavonoids, including flavanols, flavones, flavonols, flavanones, anthocyanidins, flavan-3-ols, and isoflavones.
flavonols: Substances that naturally occur in some plants, such as apples, apricots, beans, broccoli, cherries, cherry tomatoes, cranberries, kale, leeks, pears, onions, red grapes, and tea. Flavonols include quercetin, myricetin, and kaempferol.
folate: A general term for the various forms of folic acid, a B vitamin. Folate is needed to make DNA, RNA, and amino acids. It occurs naturally in foods and is found in leafy green vegetables (such as spinach and turnip greens), fruits (such as citrus fruits and juices), and dried beans and peas. The synthetic (manufactured) form of folate used in supplements and fortified foods is called folic acid.
folic acid: The form of folate (a B vitamin occurring naturally in food) that is manufactured and used in supplements and fortified foods.
follicle-stimulating hormone: FSH. A hormone made by the pituitary gland (an organ at the base of the brain) that is used in reproduction and in making estrogen and sperm.
Food and Drug Administration: FDA, Department of Health and Human Services. FDA is the Federal government agency responsible for ensuring that foods and dietary supplements are safe, wholesome and sanitary, and that drugs, medical devices, cosmetics, and food are honestly, accurately and informatively represented to the public. FDA regulates dietary supplements under a different set of regulations than those covering conventional foods and drug products (prescription and over-the-counter). The dietary supplement manufacturer is responsible for ensuring that a dietary supplement is safe before it is marketed. FDA is responsible for taking action against any unsafe dietary supplement product after it reaches the market. Generally, manufacturers do not need to get FDA approval before producing or selling dietary supplements.
Food Composition and Methods Development Laboratory: FCMDL, US Department of Agriculture. The mission of FCMDL is to develop innovative measurement systems for the determination of food components that influence human health.
fortified: When nutrients (such as vitamins and minerals) are added to a food product. For example, when calcium is added to orange juice, the orange juice is said to be "fortified with calcium". Similarly, many breakfast cereals are "fortified" with several vitamins and minerals.
fracture: A break, for example, a bone fracture.
fragile: Easily broken.
free radical: An atom or molecule made in the body that can damage cells. A free radical has at least one unpaired electron, which makes it unstable. To become stable, the free radical takes an electron away from another atom, which makes that atom unstable, and starts a chain reaction that can injure cells. Free radicals are made during chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes (metabolism). They also come from tobacco smoke, pollution, radiation from the sun and x-rays, and other sources outside the body. Free radicals damage cells, cause genetic alterations (mutations), and may play a role in cancer, heart disease, and age-related diseases (such as Alzheimer's, Parkinson's, and Lou Gehrig's diseases). Free radicals are also beneficial; they are involved in killing germs (microorganisms) and they help hormones and chemical messengers communicate with cells. Proteins (enzymes) made by the body, and vitamin C, vitamin E, and beta carotene in the diet help prevent free radical damage.
fukinolic acid: A component of black cohosh.
functional food: A conventional or modified food or ingredient that provides a health benefit (such as a lowered risk of osteoporosis) in addition to the basic nutritional functions of the food. Examples include whole, fortified, enriched, and enhanced foods.
gamma aminobutyric acid: GABA. A chemical found naturally in plants and animals. It stops nerve cells from communicating with each other and decreases electrical activity and nerve impulses in the brain. At high levels, GABA may cause a lack of coordination, sedation, and anesthesia.
gastric: Having to do with the stomach.
gastric cancer: Uncontrolled growth of abnormal cells in the stomach that spreads through the outer layers of the stomach as it grows.
gastric juice: The digestive fluid made by the stomach. It contains hydrochloric acid, enzymes, intrinsic factor, and mucus.
gastroesophageal reflux disease: GERD. A condition in which stomach acid leaks back into the esophagus because the muscle between the stomach and the esophagus does not close properly. It causes frequent heartburn and can lead to more serious health problems such as ulcers, swallowing difficulties, and cancer.
gastrointestinal: GI. Having to do with the gastrointestinal tract (the large, muscular tube that extends from the mouth to the anus, where the movement of muscles and release of hormones and enzymes digest food).
gastrointestinal motility disorder: A condition in which digestion (the process in which food is moved through the gastrointestinal tract by repeating contractions called peristalsis) is abnormal because peristalsis does not work properly. It may be caused by problems with the muscles or nerves in the intestine, or by a problem with the hormones that tell the intestines when to contract. Gastrointestinal motility disorder may cause peristalsis to stop or be too fast or too slow, which causes bloating, constipation, diarrhea, difficulty swallowing, gas, heartburn, nausea, or vomiting. It may be the result of a genetic disorder, a disease (such as diabetes), or no known cause. Examples of gastrointestinal motility disorder include irritable bowel syndrome and gastroesophageal reflux disease.
gastrointestinal tract: The large, muscular tube that extends from the mouth to the anus, where the movement of muscles and release of hormones and enzymes digest food.
gene: The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.
gene mutation: A change in the DNA that makes up a gene. Mutations can occur when a cell divides and there are errors in the way the DNA is copied. Mutations can also be caused by exposure to certain chemicals and radiation, and from infections. Some gene mutations are passed from parents to their children. Others occur during a person’s lifetime.
gene-modified: Cells that have been altered to contain different genetic material than they originally contained.
genetic disorder: A disease or disorder caused by an alteration or variation (mutation) in a gene or group of genes in the cells of an individual. Examples of genetic disorders include breast cancer, cystic fibrosis, Parkinson's disease, and celiac disease. They can be inherited or can occur without a known cause.
genetically modified food: Food made from plants or animals whose genes have been changed in the laboratory. These changes may increase crop yields, control insects and weeds, or improve nutritional content. Also called genetically engineered food.
genetics: Heredity passed from parent to offspring. Also, the identification and study of genes within an organism, their function in normal development, the consequences of gene alteration or variation (mutation), and potential treatments for genetic diseases.
genus: The name of a category that is part of the scientific classification of all organisms. Genus is located in the classification system after kingdom, phylum, class, order, and family and before the subclassification of species. Humans, for example, belong to the genus Homo and the species Homo sapiens.
ginger: The root of this plant has been used in cooking and in some cultures to treat nausea, vomiting, and certain other medical conditions. It is being studied in the treatment of nausea and vomiting caused by cancer chemotherapy. Latin name: Zingiber officianale.
gland: A small organ that makes and releases a substance such as sweat, tears, saliva, milk, a hormone, or substances that aid in digestion.
glucosamine: Glucosamine sulfate is found naturally in the fluid that surrounds your joints. It is also made from the shells of shrimp, lobsters, and crabs, and can be made in the laboratory. Some people use glucosamine to help prevent arthritis pain.
glutamine: A chemical that increases the number of messages sent between nerve cells. It is thought to be involved in learning and memory.
gluten: A protein found in wheat, rye, and barley. Eating gluten damages the small intestine in people who have celiac disease (also called gluten intolerance, gluten-sensitive enteropathy, and sprue) and can cause abdominal pain, gas, diarrhea, and other symptoms.
glycoside: A chemical compound that is made from a sugar molecule in the body or in a laboratory.
goiter: An enlarged thyroid gland. A goiter is caused by too little iodine in the diet or by other conditions, such as a growth on the thyroid or a gland that makes too much or not enough hormones.
gram: g. A measure of weight. It is a metric unit of mass equal to 0.001 kilogram (it weighs 0.035 ounce).
gynecologic: Having to do with the female reproductive tract (including the cervix, endometrium, fallopian tubes, ovaries, uterus, and vagina).
H2 receptor antagonist: A medication that reduces the amount of acid made by the stomach. It is used to treat conditions such as stomach ulcer (peptic ulcer) and gastroesophageal reflux disease.
Hamilton anxiety scale: A rating system that is used to measure the severity of the symptoms of anxiety (including worrying, restlessness, fearfulness, trouble sleeping, poor concentration or memory, depression, aches and pains, shortness of breath, nausea, sweating, and impotence).
HDL cholesterol: Good cholesterol. HDL (high-density lipoprotein) cholesterol is a type of protein that carries excess cholesterol from the arteries to the liver to be removed from the body.
health care provider: A person who supplies health care services. Health care providers include individuals with professional training (including doctors, nurses, technicians, and aides).
health claim: A statement on a food or dietary supplement product label that describes a relationship between a food, food component, or dietary supplement ingredient and the reduction in risk of developing a disease or health-related condition. For example: "Healthful diets with adequate folate may reduce a woman's risk of having a child with a brain or spinal cord birth defect."
heart attack: The blockage of an artery supplying blood and oxygen to the heart, resulting in the damage or death of a section of heart muscle.
heart failure: A condition in which the heart is unable to pump the amount of blood needed by the body. It is caused by high blood pressure, heart attack, and other disorders of the heart or blood vessels. Also called congestive heart failure.
heart palpitation: Forceful and irregular beating of the heart.
heart rhythm: The regular beating of the heart as it moves blood throughout the body.
hemochromatosis: A condition in which the body absorbs more iron than it needs and stores it in the liver, heart, and pancreas. Hemochromatosis causes liver disease, heart problems, and organ failure.
hemodialysis: The use of a machine to remove wastes and extra fluid from the blood when the kidneys have stopped working. The cleaned blood is then returned to the body.
hemoglobin: The substance inside red blood cells that carries oxygen from the lungs to the body's tissues.
hepatitis: A group of diseases in which the liver becomes enlarged and inflamed, causing fever, nausea, vomiting, abdominal pain, and dark urine.
herb: A plant used in cooking, in tea, and for medicinal purposes.
herbal: Having to do with or made from medicinal or edible plants.
high blood pressure: A blood pressure measurement of 140/90 mmHg (millimeters of mercury) or higher is considered high blood pressure (hypertension). Blood pressure is the force of blood pushing against the walls of the arteries. Blood pressure measurements are written as two numbers, for example 120/80. The first number (the systolic pressure) measures the pressure when the heart beats and pumps out blood into the arteries. The second number (the diastolic pressure) measures the pressure when the heart is at rest between beats. High blood pressure is a condition that occurs when a person's blood pressure often measures above 140/90 or regularly stays at that level or higher. This condition usually has no symptoms but can be life-threatening. It damages the arteries and increases the chance of stroke, heart attack, kidney failure, and blindness. Also called hypertension.
hives: Raised red bumps or patches on the surface of the skin that come and go and itch, burn, or sting. They are usually caused by an allergic reaction to drugs, food, or insect bites. Also called urticaria.
home birth: Having a baby in the home rather than at a birthing center or hospital.
home remedy: A traditional treatment that uses certain foods or common substances that may have medicinal properties or cause a placebo effect. Examples include chicken soup (for colds and flu), certain teas (for headache, fever, or stomach ache), and duct tape (for broken bones and plantar warts).
homeopathy: An alternative medical system based on the ideas that "like cures like" (a disease can be cured by a substance that produces similar symptoms in healthy people) and the "law of minimum dose" (the lower the dose of medication, the greater its effectiveness). Homeopathic remedies are made from plant, mineral, or animal substances and are available as pills placed under the tongue, ointments, gels, drops, and creams.
homocysteine: An amino acid (a building block of protein). At high blood levels, it may increase the risk of developing coronary heart disease, heart attack, stroke, and Alzheimer's disease. Elevated homocysteine may also increase the risk of developing osteoporosis and bone fractures.
hormone: A group of chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be manufactured.
hormone replacement therapy: HRT. Hormones (estrogen, progesterone, or both) given to women after menopause to make up for the hormones no longer made by the ovaries. Also called hormone therapy.
hot flash: A sudden, temporary onset of body warmth, flushing, and sweating (often associated with menopause).
hydrochloric acid: An acid made in the stomach. It works with enzymes (substances that speed up chemical reactions in the body) to break down proteins during digestion.
hyperthyroidism: A condition in which your thyroid gland makes more hormone than your body needs. Symptoms include weight loss, fatigue, restlessness, frequent bowel movements or diarrhea, and goiter.
hypervitaminosis A: Abnormally high amounts of vitamin A stored in the body. It can cause headache, blurred vision, nausea, vomiting, dizziness, and birth defects. Also called vitamin A toxicity.
hypothyroidism: A disorder in which the thyroid gland makes too little hormone for the body to function well. Thyroid hormones affect chemical reactions in the body, brain development, breathing, heart and nervous system functions, body temperature, muscle strength, skin dryness, menstrual cycles, cholesterol levels, and body weight.
hysterectomy: Surgery to remove the uterus. A partial hysterectomy is removal of the uterus only. A total hysterectomy is removal of the uterus and part or all of the cervix.
immune function: Substances made and action taken by cells that fight disease and infection.
immune system: A group of organs and cells that defends the body against infection, disease, and altered (mutated) cells. It includes the thymus, spleen, lymphatic system (lymph nodes and lymph vessels), bone marrow, tonsils, and white blood cells.
immunity: The condition of being protected against or resistant to an infectious disease.
immunization: A method used to cause an immune response that helps protect against a specific disease, especially an infectious one. An example is the injection given to prevent chicken pox.
impotence: In medicine, the inability to get or keep an erection firm enough for sexual intercourse. Also called erectile dysfunction.
in vitro: In the laboratory (outside the body).
in vivo: In the body.
inactive ingredient: A substance that has no medicinal effect on the body. Uses of small amounts of inactive ingredients in dietary supplements include holding the tablet together, improving the taste or smell, and increasing the stability of the key ingredient.
incidence: The number of new cases of a disease diagnosed in a specific group of people during a specific period of time. For example, the annual incidence of childhood cancer is 14.6 cases per 100,000 children aged birth to 14 years.
infant: A child younger than 12 months old.
infant formula: An artificial form of breast milk.
infection: The invasion and spread of germs in the body. The germs may be bacteria, viruses, yeast, or fungi.
infertility: The inability to produce children.
inflammation: Redness, swelling, pain, and/or a feeling of heat in an area of the body. It is a protective reaction to injury, disease, or irritation of tissues.
inflammatory bowel disease: IBD. Long-lasting (chronic) problems that cause irritation and ulcers in the digestive tract. The most common disorders are ulcerative colitis and Crohn's disease.
ingestion: Taking into the body by mouth.
ingredient: In a dietary supplement, an ingredient is a component of the product, such as the main nutrient (vitamin, mineral, herb, amino acid, or enzyme) or any binder, color, filler flavor, or sweetener. In herbal supplements, the common name and Latin name (the genus and species) of the plant is given in the ingredient list. On a dietary supplement label, the ingredients are listed by weight, with the ingredient used in the largest amount first on the list and the ingredient used in the least amount at the end of the list.
inherit: In genetics, to receive genes that are passed from parents to their children.
inhibitory neurotransmitter: A chemical that stops one nerve cell (neuron) from communicating with the next nerve cell, and decreases or blocks the transmission of nerve impulses. The main inhibitory neurotransmitter in the brain is gamma aminobutyric acid (GABA). See: excitatory neurotransmitter.
injection: Use of a syringe and needle to push fluids or drugs into the body. Also called a shot.
inorganic: Describes a substance that is not of plant or animal origin. For example, minerals are inorganic.
insomnia: Difficulty in going to sleep or in getting enough sleep.
Institute of Medicine: IOM. A private nongovernmental organization that issues reports on biomedical science, medicine, and health as requested by government agencies, private industry, and foundations.
insulin resistance: A condition in which glucose (blood sugar) cannot be absorbed by the cells and used for energy. Instead, glucose builds up in the blood and the body produces more and more insulin (which normally would help glucose get into the cells), resulting in abnormally high blood levels of both glucose and insulin. This can lead to pre-diabetes, type 2 diabetes, and other serious health problems.
interaction: A change in the way a dietary supplement acts in the body when taken with certain other supplements, medicines, or foods, or when taken with certain medical conditions. Interactions may cause the dietary supplement to be more or less effective, or cause effects on the body that are not expected.
International Unit: IU. A measurement used to measure the activity of some vitamins and other biological substances (such as enzymes and hormones).
intervention: Action taken to improve health or to treat or cure a disease.
intervention study: A clinical trial in which a group of people with the same condition is separated into two groups. One group receives the intervention (such as treatment or prevention), and the other group does not. The two groups are compared at the end of the study to see whether the intervention was more effective. For example, in an intervention study of hot flashes in postmenopausal women, one group takes black cohosh (an herbal supplement), and the other group takes a placebo (sugar pill). At the end of the study, the groups are compared to see whether the women taking black cohosh had fewer hot flashes than the women taking the placebo.
intestine: The section of the digestive tract below the stomach, including the small and large intestines, rectum, and anus.
intravenous: Into or within a vein, such as an intravenous injection.
intrinsic factor: A protein made by the stomach that is needed to absorb vitamin B₁₂ in the large intestine.
investigation: Observation, study, and examination.
iodine: A mineral the body needs to make thyroid hormones, which control metabolism (the process of turning the food you eat into energy your body can use) and many other essential functions, including bone and brain development during pregnancy and infancy. Iodine is found in seaweed, seafood, dairy products, grain products, eggs, and iodized salt.
iodize: To add iodine. For example, iodized table salt has a small amount of iodine added to it to help prevent iodine deficiency.
ionizing radiation: A type of radiation made (or given off) by x-ray procedures, radioactive substances, rays that enter the earth's atmosphere from outer space, and other sources. At high doses ionizing radiation increases chemical activity inside cells and can lead to health risks, including cancer.
IQ: Intelligence quotient. A person’s score on a standardized intelligence test.
iridoid: A category of compounds found in some plants.
iron: In nutrition, a mineral the body needs to make red blood cells, proteins, and enzymes; and for the control of cell growth and cell specialization. Iron is found in some foods, including red meats, fish, poultry, lentils, and beans.
isoferulic acid: A component of black cohosh.
isoflavones: Substances that naturally occur in some plants, especially soybeans. Isoflavones are a type of phytoestrogen and are similar to the hormone estrogen in people.
isopropanol: A substance used to kill germs and as a solvent to dissolve other substances into a solution. Also called isopropyl alcohol and rubbing alcohol.
isopropyl alcohol: A substance used to kill germs and as a solvent. Also called isopropanol and rubbing alcohol.
isotretinoin: A form of vitamin A used as a drug (such as Accutane) to treat acne and psoriasis. It is being studied in the prevention of some types of cancer. It can cause birth defects and may interfere with the ability of the liver to function properly. Also called 13-cis retinoic acid.
IU: International Unit. A measurement used to measure the activity of some vitamins and other biological substances (such as enzymes and hormones).
kava: The root of this plant has been used in traditional medicine to relieve stress, anxiety, tension, sleeplessness, and problems of menopause. The US Food and Drug Administration advises users that products containing kava may cause severe liver damage. Also called kava kava, intoxicating pepper, rauschpfeffer, tonga, and yangona. Latin name: Piper methysticum.
kidney: One of two organs that remove waste from the blood (as urine). The kidneys also make erythropoietin (a substance that stimulates red blood cell production) and help regulate blood pressure. The kidneys are located near the back under the lower ribs.
kidney disease: A condition that lessens the ability of the kidneys to filter wastes from the blood, keep blood chemical levels balanced, and make certain hormones. The two most common causes of kidney disease are diabetes and high blood pressure. People with long-term kidney disease may need dialysis or a kidney transplant to stay alive.
kidney failure: Loss of kidney function. When kidney failure is caused by an acute (sudden and short-term) condition, such as a traumatic injury or poisoning, the kidneys may be able to recover. Usually, however, kidney failure is caused by chronic (long-term) conditions such as high blood pressure and diabetes. Chronic diseases permanently damage kidney tissue; treatments include dialysis and kidney transplantation.
kidney stone: A “pebble” that forms in a kidney from salts and minerals in the urine. A small kidney stone is able to pass out of the body; a large stone may block the urinary tract and require medical help.
Kupperman index: A rating scale that is used to measure the severity of the symptoms of menopause, including hot flashes, tingling or crawling skin, difficulty sleeping, nervousness, melancholy, dizziness, weakness, joint or muscle pain, headache, and abnormal heart beat.
label: When referring to dietary supplements, information that appears on the product container, including a descriptive name of the product stating that it is a "supplement"; the name and place of business of the manufacturer, packer, or distributor; a complete list of ingredients; and each dietary ingredient contained in the product. Supplements must also include directions for use, nutrition labeling in the form of a Supplement Facts panel that identifies each dietary ingredient contained in the product and the serving size, amount, and active ingredients.
labor: The process of childbirth.
laboratory study: Research done in a laboratory. A laboratory study may use cells in test tubes or animals to find out if a drug, procedure, or other treatment is likely to be safe and useful. Laboratory studies usually take place before any testing is done in humans.
laboratory test: A medical procedure that involves testing a sample of blood, urine, tissue, or other substance collected from the body. Tests can help determine a diagnosis, plan treatment, check to see whether treatment is working, or monitor a disease over time.
lactation: The processes of making milk in the breast for feeding an infant.
lactose: A type of sugar found in milk and milk products.
laxative: A substance that moves the bowels and relieves constipation.
LDL cholesterol: Low-density lipoprotein cholesterol. A type of protein that carries cholesterol to many tissues throughout the body. High levels of LDL cholesterol increase the risk of coronary heart disease. Also called bad cholesterol.
legume: Dried beans and peas, including kidney beans, pinto beans, black beans, navy beans, lima beans, black-eyed peas, garbanzo beans (chickpeas), split peas, and lentils. Legumes are good sources of protein, iron, zinc, dietary fiber, folate, and potassium.
lens: The clear part of the eye behind the iris that changes shape to focus near and far objects onto the retina (the nerve tissue at the back of the eye that receives images and sends them to the brain).
leucovorin: A form of folate that is used as a medicine to help prevent or treat severe side effects of some chemotherapy drugs (such as methotrexate, which makes a cell unable to use folic acid, preventing DNA from being made, and stopping cells from dividing). Leucovorin also is used in the prevention or treatment of some types of anemia and in the treatment of colorectal cancer.
liver: A large organ located in the right upper abdomen. It stores nutrients that come from food, makes chemicals needed by the body, and breaks down some medicines and harmful substances so they can be removed from the body.
loop diuretic: Medication that is used to treat fluid build-up in the body and congestive heart failure. It may also be used to treat high blood pressure. Loop diuretics increase the amount of water that the body loses as urine.
lot: A batch, or a specific identified portion of a batch, having uniform character and quality within specified limits; or, an amount produced in a unit of time or quantity.
low birth weight: A baby weighing less than 5.5 pounds at birth. Low birth weight babies are at risk of sudden infant death syndrome (SIDS), infections, delayed development (for example, sitting, crawling, and talking), learning disabilities, and other health conditions, such as breathing problems, cerebral palsy, and heart disorders.
lozenge: A small, hard candy containing medicine that is dissolved in the mouth.
lung: An organ in the chest that supplies oxygen to the body and removes carbon dioxide. There are two lungs in the body.
lupus: A long-lasting autoimmune disease in which the body attacks its own healthy cells and tissues, causing inflammation (swelling, redness, pain, and warmth), and tissue damage. It can affect the skin, joints, kidneys, heart, lungs, blood vessels, and/or brain, and affects each person differently. Symptoms may include sore or swollen joints, persistent high fever, extreme fatigue, skin rashes, pain in the chest, anemia, sensitivity to sunlight, hair loss, seizures, and mouth or nose sores.
lutein: A substance found in egg yolk and colorful fruits and vegetables such as spinach, kale, collard greens, broccoli, peas, brussels sprouts, kiwi, and red seedless grapes. Lutein is a carotenoid the body cannot use to make vitamin A. It is being studied in the prevention of certain eye diseases (age-related macular degeneration and cataracts).
luteinizing hormone: LH. A hormone made in the brain that is important for the release of an egg from an ovary during the menstrual cycle and in making the hormones testosterone and estrogen.
lycopene: A substance found in tomato products. Lycopene is also found in some colorful fruits and vegetables such as watermelon, guava, papaya, apricots, pink grapefruit, and blood oranges. Lycopene is a carotenoid the body cannot use to make vitamin A. It is being studied in the prevention of some types of cancer.
lymphocyte: A type of white blood cell that is part of the immune system. It defends the body against infection, disease, and altered (mutated) cells.
lymphoma: Cancer that develops in cells of your immune system, called lymphocytes. Lymphocytes are a type of white blood cell.
macronutrients: The carbohydrates, proteins, and fats in food that give you energy and maintain your body.
macrophage: A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.
magnesium: In nutrition, a mineral the body needs for normal muscles, nerves, and bones. It also helps keep a steady heart rhythm, a healthy immune system, normal blood sugar levels and blood pressure, and is involved in making energy and protein for the body. Magnesium is found in some foods, including green vegetables, beans and peas, nuts and seeds, and whole grains.
malabsorption: A reduced ability to properly absorb nutrients. It can be caused by injury to the digestive tract, a genetic disease, or other conditions. Malabsorption can lead to malnutrition.
malaise: General discomfort that may be an early symptom of illness.
malaria: A serious, sometimes fatal disease that is caused by a parasite and spread by infected mosquitoes. It causes fatigue, high fever, sweating, shaking chills, and anemia. Malaria is common in parts of Asia, Africa, Central and South America, the Pacific islands, and areas of the Caribbean.
malformation: A defect in the physical shape or structure of an organ or body part, caused by abnormal development before birth. Examples include spina bifida (in which part of the spinal cord is on the outside of the body) and cleft palate (an opening in the roof of the mouth). Also called a deformity.
malnourished: Describes a condition caused by not getting enough calories or the right amount of key nutrients needed for health. Key nutrients include vitamins and minerals.
malnutrition: A disorder caused by a diet that does not provide enough nutrition, an unbalanced diet, a digestive system that does not work properly, or a problem with absorbing or using nutrients.
mast cell: A type of white blood cell.
measles: A group of diseases of the respiratory tract caused by a virus. Measles is highly contagious and spreads easily from person to person through coughing or sneezing. Symptoms include fever, cough, red and irritated eyes, and a spreading rash. Serious complications include pneumonia, inflammation of the brain, and death. One form called German measles may cause births defects in a fetus if a woman is infected early in her pregnancy.
mechanism of action: The means by which a substance (such as a dietary supplement) is able to produce an effect in the body.
medical history: Information about a person’s health, such as allergies, illnesses, surgeries, medications, immunizations, and the results of tests and physical exams. It may also include information about health habits, such as diet and exercise, and health information about current and past illnesses of one’s parents and other close family members.
medicinal: Having to do with the abilities of medicine to prevent and cure.
megaloblastic anemia: A disorder in which red blood cells are larger than normal, immature, and few in number, which reduces the amount of oxygen that can be carried by the blood to the body's tissues. It is caused by a deficiency in folate or vitamin B₁₂.
menopause: The time of life when a woman's menstrual periods stop. A woman is in menopause when she hasn't had a period for 12 months in a row. Also called "change of life."
menstruation: Periodic discharge of blood and tissue from the uterus. From puberty until menopause, menstruation normally occurs about every 28 days, except when a woman is pregnant.
meta-analysis: A methodical review of the results of multiple research studies. In a meta-analysis, statistical methods are used to measure the combined results of these studies and estimate an overall effect.
metabolic: Having to do with metabolism (all chemical changes that take place in a cell or organism to produce energy and basic materials needed for important life processes).
metabolism: All chemical changes that take place in a cell or an organism. These changes produce energy and basic materials needed for important life processes.
metabolize: To go through the process of metabolism (chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes).
methotrexate: A drug that blocks the body's ability to use folic acid, which is needed by growing cells such as those making up the skin, blood, digestive tract, and the cells that protect the body against infection and disease. Methotrexate is used to treat some types of cancer, arthritis, and severe skin disorders. It belongs to the group of drugs called antimetabolites.
microgram: µg or mcg. A unit of weight in the metric system equal to one millionth of a gram. (A gram is approximately one-thirtieth of an ounce.)
micronutrients: The vitamins and minerals in your diet that your body needs in small amounts.
microorganism: A living being that can be seen only through a microscope. Microorganisms include helpful and harmful bacteria, protozoa, algae, and fungi. Although viruses are not considered living organisms, they are sometimes classified as microorganisms.
microscopic: Too small to be seen without a microscope.
migraine: A type of headache that causes intense throbbing or pulsing pain, sensitivity to light and sound, and nausea and vomiting. A migraine often begins with visions of flashing lights, zigzag lines, and/or temporary loss of sight.
milligram: mg. A measure of weight. It is a metric unit of mass equal to 0.001 gram (it weighs 28,000 times less than an ounce).
mineral: In nutrition, an inorganic substance found in the earth that is required to maintain health.
miscarriage: The natural loss of a fetus before 20 weeks of pregnancy. Also called spontaneous abortion.
mitigate: To make milder or less painful.
mortality: The rate of death.
mucous membrane: The moist tissue that lines some organs and body cavities (such as the nose, mouth, and lungs) and makes mucus (a thick, slippery fluid). Also called mucosa.
multiple sclerosis: A disorder of the central nervous system marked by weakness, numbness, and loss of muscle coordination. It also causes problems with vision, speech, and bladder control. Multiple sclerosis is thought to be an autoimmune disease in which the body's immune system destroys myelin, a substance that insulates nerves and helps transmit nerve signals.
multivitamin: A product that is meant to supplement the diet. Multivitamins contain a variety of vitamins. The number and amounts of these nutrients can vary substantially by product.
multivitamin/mineral dietary supplement: MVM. A product that is meant to supplement the diet. MVMs contain a variety of vitamins and minerals. The number and amounts of these nutrients can vary substantially by product.
nasal: Having to do with the nose.
National Academies: A private nonprofit organization that brings together committees of experts in all areas of science, technology, and health policy to address important national issues and give advice to the federal government and the public. It consists of the National Academy of Sciences, the National Academy of Engineering, the Institute of Medicine, and the National Research Council.
National Center for Complementary and Alternative Medicine: NCCAM explores complementary and alternative healing practices in the context of rigorous science, trains CAM medicine researchers, provides accurate information about CAM, and helps the public and health professionals understand which CAM therapies have been proven to be safe and effective.
National Formulary of the United States Pharmacopeia: NF is a book of public pharmacopeial standards. It contains standards for medicines, dosage forms, drug substances, excipients, medical devices, and dietary supplements.
National Heart, Lung, and Blood Institute: NHLBI. An organization in the federal government that plans, conducts and supports research related to the prevention, diagnosis, treatment, and rehabilitation of patients suffering from diseases of the heart, blood vessels, and lungs; blood diseases; and sleep disorders. It also supports research on the clinical use of blood and management of blood resources. NHLBI is one of 27 Institutes and Centers that make up the National Institutes of Health.
National Institute of Standards and Technology: NIST, Department of Commerce. NIST is a nonregulatory Federal agency that promotes US innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve quality of life.
National Institutes of Health: NIH. The main organization in the federal government responsible for conducting and supporting medical research. It is composed of 27 Institutes and Centers that provide financial support to researchers in the United States and throughout the world to investigate ways to prevent, treat, and cure common and rare diseases. NIH is part of the US Department of Health and Human Services.
naturalize: To introduce a plant from one geographic region to another, and to allow it to establish itself without cultivation, and grow as if it were native to the area.
nausea: The uneasy feeling of having an urge to throw up (vomit).
necrotizing enterocolitis: A sometimes life threatening condition in which part of the tissue lining the intestines dies. It often occurs in premature infants and underweight newborn babies. Although the cause is unknown, this condition involves decreased blood flow to the intestine and possibly a bacterial infection of the tissue lining the intestine. Symptoms include a swollen abdomen, vomiting, feeding difficulties, blood in the stool, abnormal tiredness, and diarrhea.
neonate: An infant during the first month of life after birth.
neonatologist: A doctor who specializes in diagnosing and treating diseases of newborn infants.
nerve: A bundle of microscopic fibers that carries messages back and forth from the brain to other parts of the body.
nerve ending: The end of a nerve fiber that projects from the cell body of a nerve cell (neuron).
nervous system: The brain and spinal cord, including the network of nerves that carry messages back and forth between the brain and all parts of the body. The nervous system controls what the body does.
neural tube defects: Birth defects of the brain and spinal cord. They happen when the neural tube, which develops into the brain and spinal cord during the first few weeks of pregnancy, doesn't close completely. One common neural tube defect is spina bifida, in which part of the spinal cord pokes through the spine. Another common neural tube defect is anencephaly, in which major parts of the brain are missing, and the baby dies.
neurologic: Having to do with nerves and the nervous system.
neuron: A nerve cell. Neurons send chemical and electrical messages throughout the nervous system that direct the body to function, move, think, and have emotions.
neurotransmitter: A chemical messenger that is made and used by nerve cells (neurons) to communicate with one another.
neutrophil: A type of white blood cell.
niacin: A nutrient that is needed by the body to make energy from food, and for important cellular functions. Niacin is found in some foods, including poultry, beef, pork, fish, nuts, legumes, whole grains, and enriched or fortified breads and cereals. In medicine it is used as a drug to lower high blood cholesterol levels. It is one of the B vitamins. Also called nicotinamide and nicotinic acid.
NIST Standard Reference Materials®: A certified reference material issued by the National Institute of Standards and Technology (NIST) that meets additional NIST-specific certification criteria and is issued with a certificate or certificate of analysis that reports the results of its characterizations and provides information regarding the appropriate use(s) of the material.
nitrite: A chemical substance that contains nitrogen and oxygen and is used to preserve food.
nitrosamine: A chemical substance that can form in the acid conditions of the stomach. It may cause cancer.
nonorganic insomnia: A sleep disorder (difficulty in going to sleep or getting enough sleep) that occurs as a symptom of a physical or mental disease.
norethisterone acetate: A substance used in oral contraceptives (birth control pills) and as a treatment for endometriosis (a condition in which tissue that is normally found inside the uterus grows elsewhere in the abdomen).
Nurses' Health Study: An ongoing long-term study of diet, nutrition, and risk factors for major chronic disease in a large number of women in the United States.
nursing: Breastfeeding.
nutrient: A chemical compound in food that is used by the body to function and maintain health. Examples of nutrients include proteins, fats, carbohydrates, vitamins, and minerals.
nutrient content claim: A statement on a food or dietary supplement product label that describes the amount of a nutrient or dietary substance in a product. Examples of nutrient claims for dietary supplement products include fortified, high, rich in, excellent source of, good source of, and high potency.
Nutrient Data Laboratory: NDL, US Department of Agriculture. NDL develops authoritative food composition databases and state-of-the-art methods to acquire, evaluate, compile and disseminate composition data on foods available in the United States.
nutrition: The process of eating, digesting, and absorbing nutrients (such as protein, carbohydrate, fat, vitamins, minerals, and water) from food to maintain the body, grow new cells, repair tissues, and supply energy. Nutrition is also the science of food, diet, and health.
nutritional: Having to do with nutrition (eating, digesting, and absorbing the nutrients in food, and the health and disease consequences).
nutritional yeast: A food product or food additive made from yeast (a fungus). The yeast is pasteurized (heated) to prevent it from growing in a person's digestive tract. Nutritional yeast is used as a source of protein and B vitamins. Some (but not all) brands of nutritional yeast contain vitamin B₁₂. Latin name: Saccharomyces cerevisiae.
obesity: A condition characterized by an excessive amount of body fat. Obesity can be assessed by calculating the body mass index (BMI). (BMI is a number that estimates the amount of body fat on a person, based on weight and height. In adults, a BMI of 30 or higher indicates obesity. Some people, such as bodybuilders or other athletes with a lot of muscle, can be overweight without having obesity. See: overweight.
objective: Having to do with fact, experience, or direct observation rather than personal opinion or feeling.
observational study: A type of research in which individuals are observed for a specific period of time, sometimes for many years, and certain outcomes are measured. No attempt is made to affect the outcome (for example, no treatment is given).
Office of Dietary Supplements: ODS, Office of Disease Prevention, Office of Director, National Institutes of Health, Department of Health and Human Services. ODS strengthens knowledge and understanding of dietary supplements by evaluating scientific information, stimulating and supporting research, disseminating research results, and educating the public to foster an enhanced quality of life and health for the US population.
oleic acid: A fatty acid found in animal fats and vegetable oils.
omega-3 fatty acid: A main component of fats used by the body for energy and tissue growth. Omega-3s are essential fatty acids in the human diet; they are found in fish oil and certain plant and nut oils.
oral: By mouth; having to do with the mouth.
organic food: Food made from plants or animals that have been grown or raised according to the standards of the National Organic Program. The standards relate to the methods, practices, and substances used to produce and process agricultural products. Use of genetic engineering, ionizing radiation, and sewage sludge is prohibited. Cereals, fruits, and vegetables must be grown using natural fertilizers and natural pest control methods. Animals raised for meat, poultry, eggs, and dairy products must be fed organic feed and not given antibiotics or hormones to promote growth. Food produced this way can be certified and labeled as organic.
organism: A living thing such as an animal, a plant, a bacterium, or a fungus.
osteoarthritis: A disease that breaks down the cartilage in your joints. Over time, the cartilage wears away, your bones rub together, and you can have joint pain, stiffness, and swelling, typically in your fingers, thumbs, knees, hips, neck, and lower back.
osteomalacia: A condition in adults in which bones become soft and deformed because they don’t have enough calcium and phosphorus. It is usually caused by not having enough vitamin D in the diet, not getting enough sunlight, or a problem with the way the body uses vitamin D. Symptoms include bone pain and muscle weakness. When the condition occurs in children, it is called rickets.
osteoporosis: A condition in which bones become weak and brittle, increasing the chance they may break.
outcome: A specific endpoint measured in a clinical trial. Examples include weight loss, cholesterol levels, severe toxicity, worsening of disease, and death.
ovariectomize: To remove one or both ovaries (the female reproductive organs in which eggs are made and stored).
ovary: One of a pair of female reproductive glands in which the eggs (ova) are formed and stored. The ovaries are located in the pelvis, one on each side of the uterus.
overweight: An excess amount of body weight that includes muscle, bone, fat, and water. Overweight can be assessed by calculating the body mass index (BMI). (BMI is a number that estimates the amount of body fat on a person, based on weight and height. An adult with a BMI between 25 and 29.9 is considered overweight. Some people, such as bodybuilders or other athletes with a lot of muscle, can be overweight without having obesity. See: obesity.
oxazepam: A drug used to treat anxiety, sleeping disorders, irritable bowel syndrome, and the symptoms of alcohol withdrawal. It belongs to the family of drugs called benzodiazepines.
oxidation: In chemistry, the addition of oxygen atoms to a chemical substance or the loss of electrons by a chemical substance.
oxidative damage: Changes that take place in the body¹s cells as a normal result of living (such as from eating food or being exposed to sunlight). Too many of these chemical changes may increase the risk of chronic diseases like cancer, heart disease, diabetes, and age-related eye disease. Antioxidants help to protect the body from excess oxidative damage.
palpitation: A fluttering sensation in the chest, usually caused by a forceful or irregular heart beat.
pancreas: An organ in the abdomen. It makes a liquid (called pancreatic juice) containing enzymes that aid in digestion, and makes several hormones, including insulin. The pancreas is surrounded by the stomach and intestines.
pancreatic cancer: Uncontrolled growth of abnormal cells in the pancreas, an organ behind the stomach that makes pancreatic juices to help digest food, and several hormones, including insulin.
pantothenate kinase-associated neurodegeneration: An inherited condition that causes harmful compounds to build up in the brain. The condition becomes noticeable in childhood or early adolescence and get worse over time. Symptoms may include muscle spasms, stiffness, trouble walking, speech problems, and vision loss. People with this condition may develop mental disabilities, personality changes, and depression.
pantothenic acid: A nutrient that is needed by the body to make energy from food and to make red blood cells, certain hormones, and the fats found in cell membranes and in tissue surrounding nerves. Pantothenic acid is found in some foods, including meat, fish, eggs, milk products, legumes, whole grains, yeast, and vegetables.
parenteral: Having to do with providing substances for the body without using the gastrointestinal tract. Examples include an intravenous infusion, an injection under the skin, or an injection into a muscle.
Parkinson's disease: A disease in older people that causes nervous system symptoms that worsen slowly over time. Symptoms include trembling hands, arms, legs, and face; stiff arms, legs, and torso; slow movements; and impaired balance and coordination. Parkinson’s disease can also affect emotions, memory, judgment, and reasoning.
participant withdrawal: When a person enrolled as a subject in a clinical trial stops participating before the study is completed.
pediatrician: A medical doctor (physician) who specializes in the treatment of children.
peer-reviewed journal: A scholarly or scientific publication in which an article is reviewed by a board of experts before it is published. The board members determine the accuracy of the article and approve or reject it.
peppermint: A plant that has been used in traditional medicine in many parts of the world to relieve indigestion, cough, sore throat, headache, abdominal cramping, and gas. Also called brandy mint, lamb mint, and lammint. Latin name: Mentha piperita.
peptic ulcer disease: A sore or hole in the lining of the stomach or the first part of the small intestine, causing burning pain in the gut. Most ulcers are caused by an infection with a type of bacteria called Helicobacter pylori (H. pylori); other causes include long-term use of nonsteroidal anti-inflammatory drugs (such as aspirin and ibuprofen), alcohol, and tobacco.
percentile: A ranking on a scale of 100 that indicates the percent of others at or below that score. For example, a child with a weight in the 95th percentile for her age is heavier than 95 percent of all children her age; 5 percent of children her age weigh more.
perimenopausal: The time of life near menopause when a woman's menstrual periods become irregular.
peripheral artery disease: A disorder in which the arteries supplying blood to the kidneys, stomach, arms, legs, or feet become blocked by a build-up of fat and cholesterol deposits inside the arteries (atherosclerosis), causing cramping and weakness.
peristalsis: A wavelike movement of muscles that moves food and liquid through the gastrointestinal tract.
peritoneal dialysis: A way to clean the blood when the kidneys are unable to work (kidney failure) by using the lining of the abdomen as a filter. A cleansing liquid (dialysis solution) is drained from a bag through a tube (catheter) into the abdomen. Fluids and wastes flow through the lining of the abdomen and are trapped in the dialysis solution, which is then drained through the catheter, removing the extra fluids and wastes from the body.
pernicious anemia: An autoimmune disease that prevents the body from making intrinsic factor (a protein made by the stomach and needed to absorb vitamin B12 in the intestine). If left untreated, pernicious anemia causes vitamin B12 deficiency which leads to megaloblastic anemia (a disorder in which red blood cells are larger than normal, immature, and few in number, which reduces the amount of oxygen that can be carried by the blood to the body's tissues).
pharmacist: A person licensed to make and dispense (give out) prescription drugs and who has been taught how they work, how to use them, and their side effects.
Physicians' Health Study: One of two long-term studies conducted to see whether the long-term use of aspirin or various nutritional supplements such as beta-carotene, vitamins C and E, and multivitamins can prevent heart disease, cancer, and age-related eye diseases in men in the United States.
phytochemicals: A general term for the many substances that are naturally produced by plants (“phyto” means plant). Colorful fruits and vegetables, whole grains, legumes, herbs, nuts, and seeds are rich in phytochemicals. Types of phytochemicals include anthocyanins, carotenoids, flavonoids, isoflavones, and polyphenols. Also called phytonutrients.
phytoestrogen: A weak estrogen-like substance found in some plants and plant products. Isoflavones, a type of phytoestrogen, are being studied in the prevention of osteoporosis, menopausal symptoms, and some types of cancer. Soybeans are a rich source of phytoestrogens.
phytomedicine: The use of herbs and other plants for their therapeutic or medicinal qualities. Also called phytotherapy.
pica: An eating disorder in which a person eats things that are not food, such as dirt, clay, paint flakes, sand, hair, or paper. Pica is more common in young children and in people with brain injuries or developmental disabilities.
pinkeye: An infection or inflammation of the lining of the eyelid and the white part of the eye. Also called conjunctivitis.
placebo: An inactive substance or treatment that has no effect on the body and that ideally looks, smells, and tastes the same as, and is given the same way as, the active drug or treatment being tested. The effects of the active substance or treatment are compared to the effects of the placebo.
placebo-controlled: Refers to a method of studying a drug or dietary supplement in which a placebo (an inactive ingredient) is given to one group of participants, and the drug or dietary supplement being tested is given to a second group of participants. Results from the two groups are compared to see if the drug or dietary supplement being tested works better than the placebo.
placenta: The organ that delivers nutrients and oxygen and takes away carbon dioxide and other metabolic wastes from the developing fetus in the uterus.
plasma: The yellowish fluid part of blood in which blood cells are found. The plasma contains proteins that form blood clots.
platelet: Fragments of bone marrow cells (megakaryocytes) that help prevent bleeding by causing blood clots to form. Also called a thrombocyte.
pneumonia: Inflammation of one or both lungs. Bacteria, viruses, fungi, parasites, other germs, and injury can cause the lungs to become inflamed and fill with fluid. Symptoms can appear suddenly, range from mild to severe, and may include fever, chills, chest pain, cough, shortness of breath, and difficult breathing. Anyone can develop pneumonia, but it is especially dangerous in babies, older people, and people with weakened immune systems, lung disease, heart disease, or diabetes.
polycystic ovary syndrome (PCOS): An imbalance of hormones that can cause irregular ovulation, irregular menstrual periods or none at all; increased facial or body hair; acne; abnormal growths in the ovaries; weight gain; and infertility. PCOS affects females of child-bearing age and is more common in individuals with obesity or who have a mother or sister with PCOS. Having PCOS increases the risk of high blood pressure, heart disease, type 2 diabetes, and endometrial and ovarian cancer. Also called polycystic ovarian syndrome.
polyphenols: Substances that occur naturally in plants. More than 8,000 polyphenols are found in plant foods, including berries, black grapes, cherries, coffee, dark chocolate, and red onions.
polysomnography: PSG. The use of an instrument (called a polysomnograph) that is used to measure the quality of sleep and identify sleep disorders. PSG records measurements of brain activity, eye movement, and muscle tension in the face, and may include the measurement of heart rate, breathing rate, leg movements, blood pressure, and body temperature.
population: All individuals who share something in common (such as geographic location, ethnicity, gender, age, or disease). In statistics, conclusions are made about the population by studying smaller sample groups of individuals who are representative of the larger group.
porous: Full of holes.
postmenopausal: Having to do with the time after menopause. The time in a woman's life when menstrual periods stop permanently is called menopause ("change of life").
postterm baby: A baby born after the normal 42 weeks of pregnancy.
potassium: A mineral that helps the body’s nerves to function, muscles to move, and heart to beat. Potassium helps balance some of the harmful effects of salt on blood pressure.
poultry: Birds that are raised for eggs or meat, including chickens, turkeys, ducks, and geese.
premature infant: A baby born before 37 weeks of pregnancy. Normally pregnancy lasts 42 weeks. Also called preterm infant and preemie.
premenstrual syndrome (PMS): Severe symptoms that occur 1 or 2 weeks before menstruation, including cramping, bloating, and tender breasts; food cravings; mood swings and irritability; and headache and fatigue.
prenatal: Before birth; during pregnancy.
preparation: A mixture made for medicinal use.
prescription: A written order from a health care provider for medicine, therapy, or tests.
prevalence: In medicine, the percentage of a population that is affected with a specific disease at any one time.
prevent: To stop from happening.
prevention: In medicine, action taken to decrease the chance (risk) of developing a disease.
primary biliary cirrhosis: A long-lasting disease that slowly destroys bile ducts in the liver. Bile, a substance that helps digest fat, leaves the liver through these ducts. When the ducts are damaged, bile builds up and harms the liver. Over time, the disease can cause cirrhosis (scar tissue that replaces healthy tissue) and may cause the liver to stop working. Symptoms of primary biliary cirrhosis include itchy skin, fatigue, jaundice (yellowing of the eyes and skin), cholesterol deposits on the skin, bloating (fluid retention), and dry eyes or mouth.
progestin: A natural or laboratory-made substance that has some or all of the biologic effects of progesterone, a female hormone.
progression: In medicine, the course of a disease as it becomes worse. For example, as cancer progresses, it spreads in the body.
prolactin: A hormone made by the pituitary gland (an organ located at the base of the brain) and important for making breast milk and in ovulation (the release of an egg from an ovary during the menstrual cycle).
proliferation: Multiplying or increasing in number. In biology, cell proliferation occurs by a process called cell division.
proprietary: A product or technique that is developed and owned by a company or individual, cannot be used by others without approval, and may be protected by patent or copyright.
prostate cancer: Uncontrolled growth of abnormal cells in the prostate (a gland in the male reproductive system found below the bladder and in front of the rectum). Prostate cancer usually occurs in older men.
protein: A molecule made up of amino acids that the body needs for good health. Proteins are the basis of body structures such as skin and muscle, and substances such as enzymes and antibodies.
protein-energy malnutrition: A group of conditions that result when the body does not get enough protein or energy (calories), or both, to support growth and development and for the body to work properly.
proton pump inhibitor: PPI. A drug that reduces the amount of acid made by the stomach. It is used to treat peptic ulcer and gastroesophageal reflux disease.
provitamin: A substance found in some foods that the body can use to make a vitamin. An example of a provitamin is beta-carotene, which the body uses to make vitamin A. Also called a vitamin precursor.
prudent: Wise; using good judgment.
pruritus: An itching sensation that triggers the desire to scratch. Pruritus can range from mild to severe.
psoriasis: A chronic inflammatory disease in which the skin becomes swollen, red, and itchy, with patches of silvery-white scales.
pyridoxine: A form of vitamin B6.
quality control: A system to ensure that consistency and uniformity are maintained in the manufacturing of a product.
quality of life: The overall enjoyment of life, a sense of well-being, and the ability to carry out routine activities.
radiation therapy: The use of high-energy radiation from x-rays and other sources to kill cancer cells, shrink tumors, and treat other conditions.
radioactive iodine: A type of iodine that is created by nuclear power plants and nuclear bombs. It can enter your body if you are exposed to contaminated air, food, or water. In the body, radioactive iodine collects in your thyroid and can damage the gland. At careful doses, radioactive iodine is also used in nuclear medicine. It is used in imaging tests to diagnose thyroid problems, and in cancer treatment to kill thyroid tumor cells.
randomization: When referring to an experiment or clinical trial, the process by which animal or human subjects are assigned by chance to separate groups that compare different treatments or other therapies. Randomization gives each participant an equal chance of being assigned to any of the groups.
randomized clinical trial: A study in which the participants are assigned by chance to separate groups that compare different treatments. Neither the researchers nor participants can choose which group participants are assigned to. Using chance to assign people means that the groups will be similar and the treatments they receive can be compared objectively. At the time of the trial, it is not known which treatment is best. It is the patient's choice to be in a randomized trial.
Recommended Dietary Allowance: RDA. The average amount of a nutrient a healthy person should get each day. RDAs vary by age, gender and whether a woman is pregnant or breastfeeding. For example, the RDA for vitamin C is 80 mg a day for a pregnant teenager and 90 mg a day for men. RDAs are developed by the Food and Nutrition Board at the Institute of Medicine of the National Academies.
red blood cell: A cell that carries oxygen to and removes carbon dioxide from all parts of the body.
regimen: A treatment plan that specifies the dosage, schedule, and duration of treatment.
regulate: To govern, make uniform, and bring under the control of a rule, principle, or legal system. In the United States, the FDA has the authority to regulate dietary supplements.
remission: A decrease in or disappearance of signs and symptoms of disease.
reproductive age: The time of life during which a person is able to conceive a child. It begins in puberty (for men and women) and ends after menopoause (for women only).
reproductive organ: A sex organ. In females, reproductive organs include the ovaries, fallopian tubes, uterus, cervix, and vagina. In males, reproductive organs include the prostate, testes, and penis.
resin: A substance found in some plants.
respiratory: Having to do with breathing. The organs that are involved with breathing include the mouth, nose, throat (pharynx), voicebox (larynx), windpipe (trachea), air passages between the windpipe and lungs (bronchial tubes), and lungs.
respiratory tract: The organs that are involved in breathing. These include the mouth, nose, throat (pharynx), voicebox (larynx), windpipe (trachea), air passages between the windpipe and lungs (bronchial tubes), and lungs. Also called the respiratory system.
restless leg syndrome: A disorder of the nervous system that causes unpleasant or painful feelings in the legs, especially when relaxing, which results in uncontrollable urges to move them.
retina: The light-sensitive layers of nerve tissue at the back of the eye that receive images and send them as electric signals through the optic nerve to the brain.
retinal: The form of vitamin A needed for proper vision. It is made by the body from beta-carotene. Also called retinaldehyde.
retinitis pigmentosa: A group of inherited eye diseases that affect the retina (the light-sensitive part of the eye), causing a gradual loss of night vision and peripheral vision and usually resulting in partial blindness.
retinoid: A category of vitamin A compounds. The retinoids include retinol, retinal, and retinoic acid. Synthetic retinoids are manufactured for use in treating acne, psoriasis, and other skin disorders.
retinol: A form of vitamin A found only in foods that come from animals. The body can use retinol to make retinal and retinoic acid (other forms of vitamin A). Retinol is found in some foods, including beef liver, whole eggs, whole milk, margarine, and some fortified food products such as breakfast cereals. Retinol is a retinoid. Also called preformed vitamin A.
Retinol Activity Equivalent: RAE. A measure of the content and activity of vitamin A in foods.
retinol binding protein: RBP. A molecule that binds to retinol (the form of vitamin A in foods that come from animals) and carries it through the blood to tissues where it is used, and to the liver where it is stored.
retinyl ester: A form in which newly absorbed retinol (the form of vitamin A in foods that come from animals) is stored in the body.
retinyl palmitate: The main form in which retinol (the form of vitamin A in foods that come from animals) is stored in the body.
rheumatism: A group of disorders characterized by inflammation or pain in the body's connective tissues (bone and cartilage).
rheumatoid arthritis: An autoimmune disease that causes pain, swelling, and stiffness in the joints. It may cause severe joint damage, loss of function, and disability. The disease may last from months to a lifetime, and symptoms may improve and worsen over time.
rhizome: A horizontal stem that grows shallowly underground. At nodes along the rhizome, below-ground roots and above-ground shoots grow into new plants. Examples include strawberries and many types of grasses.
riboflavin: A nutrient that is needed by the body for growth, cell function, and to make energy from food. It works together with other B vitamins, and acts as an antioxidant to protect cells from free radical damage. Riboflavin is found in some foods, including liver, mushrooms, spinach and leafy green vegetables, milk and dairy products, eggs, whole grains, enriched breads and cereals, and lean meats. Also called vitamin B₂.
ribonucleic acid: RNA. A substance that tells cells how to make proteins.
rickets: A condition in children in which bones become soft and deformed because they don’t have enough calcium and phosphorus. It is caused by not having enough vitamin D in the diet or by not getting enough sunlight. In adults, this condition is called osteomalacia.
rigorous: Accurate, precise, and without deviation from standards.
risk: The chance or probability that a harmful event will occur. In health, for example, the chance that someone will develop a disease or condition.
risk factor: Something that may increase the chance of developing a disease. For example, a diet that is low in calcium and vitamin D is a risk factor for osteoporosis; smoking is a risk factor for lung cancer.
root: A part of a plant that is below ground.
safety data: Information about unwanted symptoms or diseases related to the use of drugs, medical devices, dietary supplements, food, and cosmetics.
salt substitute: A replacement for table salt used by people on low-salt diets. Salt substitutes often have potassium chloride or magnesium chloride instead of sodium chloride (salt). Salt substitutes can help people reduce the amount of sodium they consume, but these products could be harmful for people with diabetes, heart disease, or chronic kidney disease. They could also be harmful for people taking medications such as ACE inhibitors and some kinds of diuretics.
sample: A subset of individuals selected from a larger population. A sample is used to form conclusions about the general population.
saponin: A substance found in some plants. Saponins may help lower cholesterol and may have anticancer effects.
sarcoidosis: A disease in which tiny lumps (granulomas) form in cells on the inside or outside of the body. It often starts in the lungs or lymph nodes, but can occur in the skin, eyes, liver, or any organ. There may be no symptoms, or it can cause shortness of breath, fatigue, rash, pain, or death.
scale: A standardized tool used to measure or rate. For example, specific scales are used to measure a person's quality of life and the severity of pain.
scientific literature: Published peer-reviewed original research in the sciences and social sciences.
scientific study: A method of gaining knowledge by making observations, proposing educated guesses (hypotheses) to explain the observations, and testing the hypotheses in ways that have reproducible results.
screening: Checking for a disease or condition when there are no symptoms.
scurvy: A disease caused by a lack of vitamin C in the diet. Symptoms include anemia, gum disease, bleeding, and bruising.
secondhand smoke: Smoke that comes from the burning end of a cigarette, cigar, or pipe and smoke exhaled by a smoker. Inhaling secondhand smoke can cause cancer, respiratory tract infections, and heart disease.
sedative: A drug or other substance that helps cause relaxation, calmness, and sleepiness.
seizure: Sudden changes in behavior caused by excessive electrical activity in the brain.
selenium: A mineral required in very small amounts to make important enzymes that are essential for good health. Selenium is found in some foods, including plant foods grown in selenium-rich soil, and some meats and seafood.
senna: A plant used in traditional Chinese medicine and Ayurvedic medicine. The leaves are used to make a stimulant laxative that increases the frequency of bowel movements and relieves constipation. It is widely used in over-the-counter laxatives. Latin name: Senna alexandrina.
sennoside: The active ingredient in senna, a plant whose leaves are used to make a stimulant laxative that increases the frequency of bowel movements and relieves constipation.
sesquiterpene: A substance found in some plants.
sewage sludge: The material that results from processing human waste at sewage treatment facilities.
sex hormone binding globulin: SHBG. A protein made by the liver that carries a male hormone (testosterone) and a female hormone (estradiol, a form of estrogen) through the blood to body tissues. Estrogen causes levels of SHBG to increase; testosterone causes levels of SHBG to decrease.
short bowel syndrome: A condition in which people cannot absorb enough water, vitamins, minerals, protein, fat, calories, and other nutrients from the food they eat because their small intestine is too short. The intestine is too short because they have undergone surgery to remove a portion of it, it is damaged, or they were born without one.
short-chain fatty acid: A fat molecule that is composed of 6 or fewer carbon atoms. This type of fat is able to dissolve in water and is digested and absorbed more rapidly than other fats.
sickle cell disease: An inherited disease in which the body makes abnormal red blood cells that carry less oxygen from the lungs to the rest of the body. These abnormal red blood cells form clumps that get stuck in the blood vessels, causing pain, infections, and organ damage.
sign: An indication of disease that can be seen and/or measured. Examples include high fever, high blood pressure, infection, and coughing up blood.
skin cancer: Cancer that forms in tissues of the skin. Most skin cancers form in older people on parts of the body exposed to the sun or in people who have weakened immune systems.
sleep disorder: A consistent disruption of the normal pattern of sleep.
sleep latency: The period of time between settling down to go to sleep and actually falling asleep.
slow-wave sleep: Deep, nondreaming sleep.
small intestine: The part of the digestive tract that is located between the stomach and the large intestine.
solution: A liquid in which another substance has been dissolved or mixed.
soy: A plant that produces beans used in many food products. Soy products contain isoflavones (estrogen-like substances) that are being studied in the prevention of cancer, hot flashes that occur with menopause, and osteoporosis (loss of bone density). Also called soya and soybean. Latin name: Glycine max.
spasm: An abnormal and uncontrollable muscle contraction or cramp.
species: The name of a category that is part of the scientific classification of all organisms. The category species is located in the classification system after kingdom, phylum, class, order, family and genus. Humans, for example, belong to the genus Homo and the species Homo sapiens.
specimen: In medicine, a small amount of tissue or fluid from the body used for analysis, such as a blood sample.
SPF: Sun protection factor. A scale for rating the level of sunburn protection in sunscreen products. The higher the SPF, the more sunburn protection it gives.
spina bifida: A disorder in which a fetus's spine does not close properly during the first month of pregnancy. It may result in permanent damage to the nerves and spinal cord, causing paralysis of the legs and feet, bowel and bladder problems, learning problems, or hydrocephalus (too much fluid on the brain).
spleen: A fist-size organ under your ribs and above your stomach on the left side of your body. Your spleen filters your blood and breaks down old red blood cells, stores blood for emergencies such as trauma, and helps your body fight infection by making white blood cells that destroy bacteria, viruses, and other germs.
squamous cell: A type of cell that covers the inside and outside surfaces of the body. Squamous cells are flat cells that look like fish scales under a microscope. They are found in tissues that form the surface of the skin, the lining of hollow organs (such as the uterus), and passages of the respiratory tract (nose, throat, windpipe, and lungs) and digestive tract (mouth, esophagus, and rectum).
standard reference material: An authenticated material.
standard treatment: Medical therapy that is widely accepted and used by most health care professionals as an appropriate treatment for a particular condition.
standardization: A process manufacturers may use to ensure batch-to-batch consistency of their products and to provide a measure of quality control. Dietary supplements are not required to be standardized in the United States. Some manufacturers use the term incorrectly or to mean different things and the presence of the word "standardized" on a supplement label does not necessarily indicate a level of product quality.
statin: A drug used to treat high cholesterol. Statins lower the amount of cholesterol and certain fats in the blood.
statistical difference: A mathematical measure of variation between groups that is greater than what might be expected to happen by chance alone.
statistical effect: Describes a mathematical measure of difference between groups.
statistically significant: In medicine, a mathematical measure of difference between two or more groups receiving different treatments that is greater than what might be expected to happen by chance alone.
status: The state or condition. For example, a person’s vitamin B12 status is measured by doing a laboratory test on a blood sample.
stimulant: A substance that increases brain activity, alertness, attention, blood pressure, heart rate, breathing, and energy.
stolon: A specialized stem that grows horizontally on top of the ground; roots and new plants form at nodes along the stolon. An example is the strawberry plant.
stool: The waste matter passed in a bowel movement; feces.
stroke: A loss of blood flow to part of the brain. Strokes are caused by blood clots or broken blood vessels in the brain, and result in damage to a section of brain tissue. Symptoms include dizziness, numbness, weakness on one side of the body, and problems with talking or understanding language. The chance (risk) of stroke is increased by high blood pressure, older age, smoking, diabetes, high cholesterol, heart disease, a family history of stroke, and a build-up of fatty material inside the coronary arteries (atherosclerosis). See also NIH publication: Know Stroke. Know the Signs. Act in Time. http://www.ninds.nih.gov/disorders/stroke/knowstroke.htm
structure/function claim: A statement on a food or dietary supplement label that describes how a product may affect the organs or systems of the body; a specific disease cannot be mentioned. Structure/function claims do not require FDA approval, but the manufacturer must provide the FDA with the text of the claim within 30 days of putting the product on the market. Labels must also include a disclaimer that reads, "This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease." For example: "Calcium builds strong bones."
study design: A plan for collecting and using information to properly test an educated guess (hypothesis).
stunted growth: Not able to reach the expected height, size, or level of development for a child’s age.
subclinical: Having to do with the early stage of a disease, before signs and symptoms appear.
subcutaneous: Beneath the skin.
subjective: Influenced by experience, knowledge, opinion, or emotion; not based on facts alone.
subjective improvement: An improvement that is reported by a person but cannot be measured by a healthcare provider. For example, "I feel better."
subjective measurement: A method of determining an effect when precise numbers cannot be known. Examples of tools used in subjective measurement include questionnaires and sliding scales. For example, "On a scale of 1 to 10, my pain is an 8."
sudden cardiac death: A condition in which the heart suddenly stops beating. This usually causes death if not treated within minutes.
sunscreen: A substance that helps protect the skin from the sun's harmful rays. Sunscreens reflect, absorb, and scatter ultraviolet A and ultraviolet B light to provide protection against both types of light. Using lotions, creams, or gels that contain sunscreens can help protect the skin from premature aging and damage that may lead to skin cancer.
supplement: A nutrient that may be added to the diet to increase the intake of that nutrient. Sometimes used to mean dietary supplement.
symptom: A feeling of sickness that an individual can sense, but that cannot be measured by a healthcare professional. Examples include headache, tiredness, stomach ache, depression, and pain.
synaptic cleft: The gap between nerve cells (neurons). Nerve cells communicate with each other by sending and receiving chemical messages (neurotransmitters) across the synaptic cleft.
synaptosome: A sac of nerve-ending particles that have been processed in a centrifuge in the laboratory. Synaptosomes are used in lab tests to study communication between nerve cells (neurons).
synergism: The interaction of two or more substances to produce an effect that is greater than what would be expected by adding the separate effects of each.
synthesis: Creating something new by putting together separate parts (such as, chemicals). For example, sunlight is needed for vitamin D synthesis in the skin.
synthetic: Made by combining parts to make a whole; usually having to do with substances that are artificial or manufactured.
systematic review: A structured method of identifying, selecting, and analyzing appropriate research to answer a specific question.
tamoxifen: A drug used to treat breast cancer and to prevent cancer in women who have a high risk of developing breast cancer. Tamoxifen blocks the effects of the hormone estrogen in the breast. It belongs to the family of drugs called antiestrogens.
tea: A drink made by adding boiling water to fresh or dried herbs and steeping (soaking) them. It may be drunk either hot or cold. Also called an infusion.
theoretical: Describes an assumption that is supported by scientific evidence, but has not been proven.
therapeutic: Used to treat disease and help healing take place.
therapeutic effect: The beneficial response or outcome of a treatment or prevention measure.
thiamin: An important nutrient that is needed by the body to make energy from food, for cell and muscle function, and for a healthy nervous system. Thiamin is found in some foods, including enriched breads and cereals, legumes, liver, nuts, pork, and whole grains.
thiazide diuretic: A drug used in the treatment of high blood pressure and swelling caused by excess fluid in body tissues (edema). It increases the amount of urine made by the body.
thyroid: A gland located in the front of the neck, below the larynx (Adam’s apple). The thyroid makes hormones that circulate in the bloodstream and affect brain development, metabolism, weight, breathing, heart rate, blood pressure, nervous system functions, body temperature, muscle strength, skin dryness, menstrual cycles, and cholesterol levels.
tincture: A liquid made by soaking an herb in a solution of alcohol and water. It is used for concentrating and preserving an herb and may be made in different strengths that are expressed as ratios of the weight of the dried herb to the volume or weight of the finished product.
tissue: A group or layer of cells in a living organism that work together to perform a specific function.
toddler: A child between the ages of 12 months and 3 years.
tolerance: The ability to take a drug or dietary supplement without discomfort or unwanted side effects. Also, a condition that occurs when the body gets used to a drug or dietary supplement so that either larger amounts or a different drug or supplement is needed to get the same effect originally experienced.
toxic: Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted health effects.
toxicity: The degree to which something is poisonous (toxic).
tranquilizer: A drug used to treat anxiety and insomnia. It belongs to the family of drugs called central nervous system (CNS) depressants. An example is valium.
transplant: The replacement of tissue with tissue from the person's own body or from another person.
treat: To care for a patient with a disease by using medicine, surgery, or other approaches.
tremor: A trembling or shaking in one or more parts of the body, usually the hands. An individual can also have tremors in the arms, head, face, vocal cords, torso, and legs.
triglyceride: A type of fat found in your blood. When you eat more than you need, your body turns the excess calories into triglycerides. High blood levels of triglycerides can increase your risk of heart disease, heart attack, and stroke.
triterpene: A chemical compound found in some plants.
triterpene glycoside: A family of chemicals found in some plants. Examples of triterpene glycosides are acetein, cimicifugoside, and 26-deoxyacetin, which are components of the herb black cohosh.
Tube feeding: A way of giving medicines and liquids, including liquid foods, through a tube that goes to the stomach or small intestine.
tuberculosis: A disease caused by a specific type of bacteria that spreads from one person to another through the air. Tuberculosis can affect many parts of the body, but most often affects the lungs. A person may not have symptoms of tuberculosis for years, but they may appear when the patient becomes ill with a serious condition like diabetes, AIDS, or cancer. Tuberculosis can usually be treated and cured with antibiotics. Also called TB.
tumor: An abnormal growth of tissue that forms when cells divide more often than they should. Tumors may be benign (not cancer) or malignant (cancer).
ulcer: A sore on the skin or in the lining of an organ or other tissue that deepens as cells die. Ulcers form where swelling, redness, pain, and warmth (inflammation) have killed the cells, then bleed and produce pus.
ulcerative colitis: Chronic inflammation of the colon that causes ulcers to form in its lining. This condition is marked by abdominal pain, cramps, and loose discharges of pus, blood, and mucus from the bowel.
ultraviolet light: Invisible rays that are part of the energy that comes from the sun. Ultraviolet light also comes from sun lamps and tanning beds. It can damage the skin and cause skin cancer.
UNICEF: An organization of the United Nations that provides food, clothing, health care, and support to women and children.
uniformity: The quality of being consistently the same and not varying or fluctuating in color, size, weight, composition, or any other physical feature.
United Status Pharmacopeia: USP is a voluntary, science-based, nonprofit, standards-setting organization. It is an official public standards-setting authority for all prescription and over-the-counter medicines and other health care products manufactured or sold in the United States. USP also sets widely recognized standards for food ingredients and dietary supplements. Its publications, the USP and the National Formulary (NF), are recognized in the US Federal Food, Drug, and Cosmetic Act as official compendia for the United States. Monographs for dietary supplements and ingredients appear in a separate section of the USP. The tests and procedures cited in the monographs require the use of official USP Reference Standards.
upper limit: UL. The largest daily intake of a nutrient considered safe for most people. Taking more than the UL is not recommended and may be harmful. The UL for each nutrient is set by the Food and Nutrition Board at the National Academies of Sciences, Engineering, and Medicine. For example, the UL for vitamin A is 3,000 micrograms/day. Women who consume more than this amount every day shortly before or during pregnancy have an increased chance (risk) of having a baby with a birth defect. Also called the tolerable upper intake level.
urinary tract: The organs involved in making and relieving the body of urine, including the kidneys, ureters, bladder, and urethra.
urine: Excess liquids and wastes that have been filtered from the blood by the kidneys, stored in the bladder, and removed from the body through the urethra (the tube that carries urine from the bladder to outside the body).
US Department of Agriculture: USDA promotes America's health through food and nutrition, and advances the science of nutrition by monitoring food and nutrient consumption and updating nutrient requirements and food composition data. USDA is responsible for food safety, improving nutrition and health by providing food assistance and nutrition education, expanding markets for agricultural products, managing and protecting US public and private lands, and providing financial programs to improve the economy and quality of rural American life.
USDA National Nutrient Database: A searchable database of the nutrient content of more than 7,000 foods in the United States. The database can be accessed online at: http://www.nal.usda.gov/fnic/foodcomp/search/.
uterus: The small, hollow, pear-shaped organ in a woman's pelvis in which a fetus develops.
vagina: The muscular canal between the uterus and the outside of the body.
valepotriate: An active component of valerian. It has a sedative effect.
valerenic acid: An active component of valerian. It is has a sedative effect.
valerian: The roots of this plant are used by some cultures as an ingredient in mild sedatives and sleep aids for nervous tension and insomnia. It is being studied in improving sleep in patients undergoing treatment for cancer. Latin name: Valeriana officinalis.
vascular: Having to do with blood vessels.
vasomotor: Having to do with the narrowing and widening of blood vessels.
vegan: A person who eats only plant-based foods. Vegans do not eat meat, poultry, fish, eggs, milk, dairy products, or honey, and do not use leather, silk, or wool, or soaps and cosmetics that are made from animal products.
vegetarian diet: A diet based on foods that come from plants, such as vegetables, beans, fruits and grains. There are many types of vegetarian diets, some including foods that come from animals. A diet that also contains eggs and dairy products is called lacto-ovo vegetarian. Strict vegetarian and vegan diets include only foods made from plants. In addition, people who follow a vegan diet also may choose not to use products that come from animals such as honey, leather, fur, silk, and wool.
vegetarianism: The practice of avoiding all or most animal products for environmental, philosophical, and health reasons. Vegetarians (people who practice vegetarianism) eat a diet based on foods that come from plants and may include some dairy products and eggs. See: vegetarian diet.
Ventilator: In medicine, a machine used to help a patient breathe. Also called respirator.
very low birth weight: A baby weighing less than 3 pounds, 4 ounces at birth.
virus: An organism that can grow and multiply only inside the cells of living humans, plants, or animals. It is able to change (mutate) as it multiplies, which makes viral illnesses difficult to treat. Viruses cause many infections and diseases such as the common cold, AIDS (acquired immunodeficiency syndrome), herpes, and hepatitis.
vitamin: A nutrient that the body needs in small amounts to function and maintain health. Examples are vitamins A, C, and E.
vitamin A: A general term for a group of compounds that includes provitamin A carotenoids (found in foods that come from plants) and retinol (preformed vitamin A found in foods that come from animals). The body can use retinol to make retinal and retinoic acid (other forms of vitamin A). Vitamin A plays an important role in vision, bone growth, reproduction, immunity, cell development, and skin health. Vitamin A is found in some foods, including eggs, liver, fortified milk, cheese, leafy green vegetables (such as spinach, kale, turnip greens, collards, and romaine lettuce), broccoli, dark orange fruits and vegetables (such as apricots, carrots, pumpkin, sweet potatoes, papaya, mango, and cantaloupe), and red bell pepper.
vitamin B₁₂: A group of chemical compounds that contain cobalt and are needed for certain chemical reactions in the body. Vitamin B₁₂ is involved in maintaining healthy nerve cells and red blood cells. It is needed to make DNA (the genetic material in all cells), and is required for the metabolism (chemical changes that take place in the tissues to produce energy and the basic materials needed by the body) of carbohydrate, fat, and protein. Also called cobalamin. For more information see the NIH Office of Dietary Supplements Vitamin B₁₂ fact sheet.
vitamin B₆: A group of water-soluble chemical compounds, including pyridoxine, pyridoxal, and pyridoxamine. It is involved in protein metabolism, is needed for the nervous system and immune system to work efficiently, and is needed to make hemoglobin (a molecule within red blood cells that carries oxygen to tissues). It also helps maintain blood glucose (sugar) within a normal range. For more information see the NIH Office of Dietary Supplements Vitamin B₆ fact sheet.
vitamin C: A nutrient needed by the body to make collagen (a protein found in cartilage, tendons, ligaments, bone, and blood vessels), to absorb iron from food, and for wound healing. It is an antioxidant and protects cells from free radical damage. Vitamin C is found in some foods including citrus fruits, strawberries, peppers, dark green vegetables, tomatoes, and potatoes. Also called ascorbic acid.
vitamin D: A nutrient that is obtained from the diet and can be made in the skin after exposure to sunlight. Vitamin D acts as a hormone. It helps to form and maintain strong bones, maintain normal blood levels of calcium and phosphorus, and increase calcium absorption; it also helps to maintain a healthy immune system and control cell growth. Vitamin D is found in some foods, including some types of fatty fish, and milk and breakfast cereals that are fortified with vitamin D.
vitamin E: A nutrient needed by the body to help keep the immune system healthy and to repair damage to DNA. It is an antioxidant that protects cells from free radical damage. Vitamin E is found in some foods, including vegetable oils, nuts and seeds, fortified breakfast cereals, and spinach, broccoli, kiwi, and mangos.
vitamin K: A nutrient needed by the body to function and stay healthy. It helps form blood clots and maintain strong bones. Vitamin K is found in some foods, including green leafy vegetables, broccoli, liver, and vegetable oils. It is also made by bacteria that live in the large intestine.
volatile: Describes a substance that evaporates quickly.
volatile oil: An oil that vaporizes easily and is responsible for the fragrance of some plants.
volume: The amount of space taken up by a substance; the amount of space a container can hold.
water soluble vitamin: A vitamin that dissolves in water and is excreted in the urine. Foods that supply water-soluble vitamins need to be eaten regularly because they cannot be stored in the body. Water-soluble vitamins include vitamin C, biotin, folate, niacin, pantothenic acid, riboflavin (vitamin B₂), thiamin, and vitamin B₆.
well-being: The state of feeling healthy, happy, and content. Well-being is affected by things such as physical and mental health, income, education, social support, attitude, values, stress, security, and other qualities of life.
Wernicke-Korsakoff syndrome: A brain disorder caused by thiamine (vitamin B1) deficiency, usually as a result of alcohol abuse. Symptoms include confusion, vision problems, lack of muscle control, memory loss, tremors, hallucinations, and coma.
white blood cell: WBC. A cell made by the bone marrow that helps the body fight infection and disease. WBCs include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells.
whole grain: Unprocessed seeds of edible grasses, including brown rice, buckwheat, bulgur, millet, popcorn, oats, quinoa, whole-grain barley, whole rye, whole wheat, and wild rice. Grains that are ground, cracked, or flaked can be labeled whole grain if they have the same amount of bran, germ, and endosperm (the inner part of the seed kernel) as the intact grain. Whole grains are sources of iron, magnesium, selenium, B vitamins, and dietary fiber. Eating whole grains may help lower the risk of heart disease, obesity, and type 2 diabetes.
World Health Organization: WHO. An agency of the United Nations that is concerned with worldwide health.
zeaxanthin: A substance found in corn, leafy green vegetables, persimmons, tangerines, seeds, and egg yolk. It is a carotenoid the body cannot use to make vitamin A. It is being studied in the prevention of certain eye diseases (age-related macular degeneration and cataracts).
zinc: A mineral found in most cells of the body. It helps enzymes work properly, helps maintain a healthy immune system, helps maintain the senses of taste and smell, and is needed for wound healing, making DNA, and normal growth and development during pregnancy, childhood, and adolescence. Zinc is found in some foods, including oysters, red meat, poultry, beans, nuts, certain seafood, whole grains, fortified breakfast cereals, and dairy products.