The Scoop - February 2011

Welcome to the first issue of The Scoop!

The Scoop is for health-conscious people like you who may use dietary supplements or are curious about them but have some questions. It will bring you information and news that you can use to make more informed decisions about taking dietary supplements.

Some issues of The Scoop will address questions we’ve received about supplements. Others will focus on one topic, such as multivitamins or dietary supplements and aging. But the goal of each issue remains the same—to help you navigate the always interesting but sometimes confusing world of dietary supplements.

The Scoop is brought to you by the Office of the Dietary Supplements (ODS) at the National Institutes of Health (NIH)—the world’s largest medical research agency. ODS promotes high-quality scientific research on the many different ingredients in dietary supplements. We also provide reliable information on these products to consumers and scientists. We hope you find The Scoop valuable.

We designed our new Web site with you in mind.

The NIH Office of Dietary Supplements Web site is newly designed with consumers like you in mind. Under the Health Information tab, you’ll find accurate, up-to-date information to help you make educated decisions about dietary supplements. We also offer a series of consumer-oriented fact sheets on dietary supplements to complement those written for health care professionals.

Dietary supplements: there’s a free app for that!

My Dietary Supplements
(myDS) is a new, free mobile app for the Apple iPhone and iPad that provides an easy way to keep track of the vitamins, minerals, herbs, and other supplements you take.

Dietary supplements: what you need to know.

The NIH Office of Dietary Supplements has created a brochure—“Dietary Supplements: What You Need To Know”—that serves as a one-stop resource for accurate information about dietary supplements. This brochure talks about effectiveness, safety and risk, quality, regulation, and other important factors to consider before buying and taking dietary supplements. The brochure also provides an extensive list of other relevant Federal Government information resources.

Should I take a vitamin D supplement?

It depends. You need vitamin D for strong, healthy bones and to help prevent osteoporosis. Researchers are also studying vitamin D to see if it affects your risk of getting diseases such as diabetes and cancer, but they still don't fully understand all of its effects in the body.

A scientific committee recently issued new recommended intakes for vitamin D. Most children and adults should get 600 International Units (IUs) a day, while those age 70 and older need 800 IUs.

It’s always best to get nutrients from food first, if you can, before taking supplements. Good sources of vitamin D include tuna and fortified milk. Our bodies also make vitamin D when our skin is exposed to the sun. Knowing exactly how much vitamin D you’re getting can be difficult. Your health care provider can help you determine whether you might need a vitamin D supplement based on such factors as the foods you eat, your skin type, and the amount of sun you're exposed to. Your health care provider can also test your vitamin D blood levels.

What is the difference between vitamin D2 and vitamin D3?

Vitamin D comes in two forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). When taken at the recommended levels listed above, both increase the amount of vitamin D in your blood equally well. But if you're taking a very large dose on the advice of your health care provider, the D3 form may be more effective than the same amount of D2.

Have more questions? See our fact sheets on vitamin D.

Can vitamin C prevent colds or make them shorter?

This is a common question and one that many scientists have tried to answer. Overall, the research shows that for most people, taking vitamin C regularly does not reduce the chances of getting the common cold. Vitamin C supplements might slightly shorten the duration of a cold and lessen its severity. However, taking vitamin C after the onset of cold symptoms doesn’t appear to help.

Taking too much vitamin C can cause diarrhea, nausea, and stomach cramps. Most adults need between 75 and 90 milligrams (mg) of vitamin C per day and shouldn't get more than 2,000 mg.

Have more questions? See our fact sheets on vitamin C.

How do I know if a dietary supplement contains what the label says or if it might be contaminated?

Manufacturers of supplements must follow good manufacturing practices to help ensure their identity, purity, strength, and composition. These practices are designed to prevent problems such as including the wrong ingredient, adding the wrong amount of an ingredient, or contamination. The U.S. Food and Drug Administration has begun to periodically inspect facilities that manufacture dietary supplements, but it does not routinely analyze the content of dietary supplements.

Several independent organizations test the quality of dietary supplements and allow products that pass their tests to display their seals of approval. These seals provide assurance that the product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful amounts of contaminants. Seals of approval don't guarantee that a product is safe or effective. Organizations that offer this testing include the U.S. Pharmacopeia, ConsumerLab.com, NSF International, and the Natural Products Association.

I'm thinking about using an herbal product but there are so many different brands. I don't know which one to buy or how much to take.

Many herbs are available in different forms, so it can be hard to compare one product to another. This is partly because scientists have not identified or clearly defined the components responsible for the effects of most herbs or the best amount to take. If you want to try an herbal product, talk with your health care provider first and ask whether he or she can recommend a particular brand and dosage.

Safety is also an important consideration. Many people believe that products labeled "natural" are safe and good for them. This is not necessarily true. The safety of an herbal supplement depends on many things, such as its chemical makeup, how it works in the body, how it's prepared, and how much you take. Many supplements contain active ingredients that can have strong effects in the body and can interact with certain prescription drugs in ways that might cause problems. So, always be alert to the possibility of unexpected side effects, especially when taking a new product.

Have more questions? See our background fact sheet on botanical dietary supplements.