Medical Health Encyclopedia

Before selling any supplement introduced after 1994, manufacturers must submit information as to why the product is considered safe for people. The FDA may refuse to allow it on the market if it finds the evidence insufficient. The FDA does not require manufacturers to provide any scientific evidence that dietary supplements are safe and effective before a product is sold (unlike drugs, which must be proven both safe and effective through clinical trials).  If a supplement causes side effects in people once it is for sale, the government may place restrictions on the supplement or withdraw it from the market. The FDA may also withdraw products from the market if their labels are misleading or false.

People Who Should Take Vitamin Supplements

About 30% of Americans take at least one vitamin or mineral supplement daily. In a large study that examined the death rates of 11,000 people, however, there was no difference in mortality rate between those who took vitamin supplements and those who didn't. If a diet is healthy, most people do not need vitamins, but there are some exceptions. Nevertheless, a number of experts do recommend that adults take a multivitamin every day.

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Pregnant and Breast-Feeding Women. Women who are pregnant or who are breast-feeding generally need additional vitamins. The B vitamins are particularly important. Women who are vegetarians must be sure to avoid deficiencies, which can harm their offspring.Folic acid reduces the risk for neural tube defects and possibly facial abnormalities, such as cleft palate. Multivitamins that contain folic acid also appear to be somewhat protective. Taking extra folic acid plus multivitamin supplements (which have additional benefits) and starting them before a woman actually becomes pregnant is the optimal approach.

The human body stores several years' worth of vitamin B12, so nutritional deficiency of this vitamin is extremely rare. Although, people who follow a strict vegetarian diet and do not consume eggs or dairy products may require vitamin B12 supplements.