The Scoop - March 2016

All B vitamins go by two or even three different names. Here’s a quick guide. The names in bold text are the ones most commonly used:

Many older adults might be vitamin B12 deficient

According to a recent study published in Applied Physiology, Nutrition, and Metabolism, many older adults have a vitamin B12 deficiency. The study took place in Ontario, Canada, among 412 adults who were 83 years old on average and living in long-term care homes. Researchers found that about 14% of the residents were vitamin B12 deficient when they moved into long-term care. Not surprisingly, those who were taking vitamin B12 supplements (either orally or by injection) were less likely to have a deficiency than those who weren’t. A vitamin B12 deficiency can cause many symptoms including tiredness, weakness, constipation, loss of appetite, depression, confusion, and numbness and tingling in the hands and feet. This study highlights the importance of checking vitamin B12 levels in older adults and starting treatment if a deficiency is found.

New study links folic acid supplements to reduced risk of preeclampsia in certain women during pregnancy

In addition to lowering the risk of neural tube defects, taking folic acid supplements during pregnancy might also lower the chances of developing preeclampsia, according to a study recently published in PLoS ONE. Preeclampsia is a serious medical condition in which a pregnant woman develops high blood pressure and kidney problems that cause protein to spill into the urine. Preeclampsia is a leading cause of sickness and death in pregnant women and their newborn babies, affecting about 1 in 20 pregnancies. The study tracked 7,669 pregnant women in Canada and correlated their use of folic acid supplements during the early part of the second trimester (around 4 months) with the chances of developing preeclampsia. The researchers analyzed the data separately for women at low risk of preeclampsia and those at high risk due to being obese, having chronic high blood pressure or diabetes, being pregnant with twins or triplets, or having had preeclampsia in the past. Overall, about 95% of the women were taking folic acid, most by taking prenatal or regular multivitamins containing 1,000 mcg or more of folic acid. Results showed that high-risk women who took supplements containing folic acid had a much lower chance of developing preeclampsia than those who did not take folic acid. Among low-risk women, however, taking folic acid did not significantly affect their chances of developing preeclampsia. This study provides additional support for taking supplements containing folic acid during pregnancy.

Almost everyone is familiar with some of the B vitamins like vitamin B6 and vitamin B12, but you may not know that several other vitamins that usually go by different names are also classified as B vitamins. They include thiamin, riboflavin, niacin, pantothenic acid, biotin, and folic acid. As a group, the B vitamins often work together in the body and have many important roles including metabolizing fats and proteins, and making red blood cells and DNA. The B vitamins are water soluble, so the body doesn’t store them as much as fat-soluble vitamins such as vitamin A. But many of them still have upper limits, so like other vitamins and minerals, it’s important to get enough of the B vitamins, but not too much. Below are some commonly asked questions about several of the B vitamins. Our vitamin and mineral fact sheets provide additional information.

1. My supplement has 1,000 mcg of vitamin B12, and the label says that it provides 16,667% of the DV. Is that correct? It seems like too much.

Yes, the supplement is labeled correctly. The daily value (DV) for vitamin B12 is only 6 micrograms (mcg), so a 1,000-mcg supplement provides 16,667% of the DV. Multivitamin/mineral supplements frequently provide around 100% of the DV for many nutrients, but it is common to find supplements of vitamin B12 (and other B vitamins) that provide much higher doses. Even though most people don’t need such high amounts, vitamin B12 does not have an upper limit, so taking a lot isn’t likely to cause any problems.

Most people consume enough vitamin B12 from the foods they eat, but only animal foods naturally contain vitamin B12. Therefore, vegetarians—especially vegans who eat no animal products—need to get vitamin B12 from either fortified foods, such as many breakfast cereals and nutritional yeast products, or dietary supplements. In addition, some people—especially adults over age 50—have trouble absorbing the form of vitamin B12 that is naturally found in food. For these reasons, as much as 15% of the population might have a vitamin B12 deficiency. Vitamin B12 injections (which are administered by your health care provider) or vitamin B12 supplements can help correct a deficiency.

Have more questions? See our fact sheet on vitamin B12.

2. I suffer from migraine headaches, and I’ve heard that riboflavin might help. Is riboflavin safe to take for migraines?

Riboflavin is a B vitamin that is sometimes called vitamin B2. A number of foods, including eggs, organ meats (such as kidneys and liver), lean meats, low-fat milk, and green vegetables, contain riboflavin. It’s also added to enriched cereals, bread, and grain products.

Some studies show that riboflavin supplements might help prevent migraine headaches, but other studies do not. Even though not all studies agree, several professional societies recommend trying riboflavin because it might be effective and has few side effects. The Canadian Headache Society, for example, recommends 400 milligrams (mg)/day of riboflavin, under the guidance of a health care provider, for preventing migraines. This is a very large daily dose, so we advise talking with your health care provider about riboflavin and migraines to find out what’s best for you.

Have more questions? See our fact sheet on riboflavin.

3. I know that the B vitamin folic acid helps prevent birth defects, so it’s important to take during pregnancy, but why are women supposed to take it before getting pregnant?

Yes, getting enough folic acid (also called folate) helps prevent birth defects, especially a kind called neural tube defects. These types of birth defects occur when the neural tube (where the brain and spinal cord form) doesn’t close properly in the fetus.

The neural tube closes very early in pregnancy—only 3 to 4 weeks after conception. This is right around the time most women realize they are pregnant, so waiting to take folic acid until you find out that you are pregnant might be too late.

If you are a woman or teenage girl who could become pregnant, you should get 400 mcg of folic acid per day from dietary supplements and/or fortified foods (such as enriched breads, cereals, pastas, and other grain products). This is in addition to the amount you get naturally from foods and beverages. The recommended amount goes up to 600 mcg per day once a woman is pregnant because folic acid has many other important functions during the remaining months of pregnancy.

Have more questions about folic acid? See our fact sheet on folate.