Healthy people who eat a variety of foods using the guidelines of MyPyramid should be able to obtain all the vitamins needed to maintain good health. However, some people take supplements because they believe that (1) food no longer contains the right nutrients in adequate quantities; (2) supplements can “bulk up” muscles and enhance athletic performance; (3) vitamins provide needed energy; and (4) vitamins and minerals can cure anything, including heart trouble, the common cold, and cancer.
The facts are as follows: (1) A balanced diet would provide for the nutritional needs of healthy people, but many do not follow a healthy eating plan, relying on fast food; processed foods; and heat, eat, and go foods. Therefore, the American Medical Association has recommended that everyone take one multiple vitamin a day. (2) No amount of vitamins will build muscles; only weight lifting will do that (3) Vitamins do not provide energy themselves. They help to release the energy within the carbohydrates, proteins, and fats that people ingest. (4) Only certain diseases caused by vitamin deficiencies (such as beriberi, scurvy, rickets) can be cured with the help of vitamin supplements. Heart disease, cancer, and the com-mon cold cannot.
Almost everyone can take a daily multivitamin and mineral supplement without fear of toxicity, but a megadose (10 times the RDA/DRI) to correct a deficiency or to help prevent disease should be prescribed by a physician. If a multivitamin-mineral is taken as a supplement, it is best not to exceed 100% of the RDA/DRI for each vitamin and mineral. An excess of one vitamin or one mineral can negatively affect the absorption or utilization of other vitamins and minerals. If vitamin supplements are thought to be necessary, it is best to consult a physician or registered dietitian.
Herbal products also are included under the heading “dietary supple-ments.” Some people are interested in herbs because they believe certain ones can improve their health, they require no prescription, and they are often less expensive than prescription drugs.
The U.S. Food and Drug Administration (FDA) requires that manufactur-ers of prescription and over-the-counter drugs run, monitor, and report results of clinical trials of their products before selling them. Doses are established, and side effects and adverse reactions are reported in scientific journals. Also the FDA can inspect drug manufacturing facilities to confirm the purity of ingredients.
The Dietary Supplement Health and Education Act of 1994 exempts dietary supplements from FDA evaluation unless the FDA has evidence that a product is harmful. But before a suspect product can be removed from store shelves, theFDA must prove it is not safe. Manufacturers of supplements cannot claim their products can treat or prevent diseases, but they can make “structure-function” claims. For example, they cannot say vitamin A prevents cancer, but they can say vitamin A has antioxidant properties and antioxidants have been linked to reduced rates of cancer.
Misinformation concerning supplements is widely available. Health care professionals must stay well informed concerning supplements, provide accurate information to their clients, and urge clients to consult with their physicians or registered dietitians before using any supplement. Some herbal products may indeed be helpful, but some may be harmful.