Vitamin and Mineral Dietary Supplements

lists the vitamins according to whether they are fat- or water-soluble. Those minerals necessary for a healthy diet are boron, calcium, chromium, copper, iodine, iron, magnesium, manganese, phosphorus, potassium, selenium, and zinc. To prevent illness and death from vitamin and mineral deficiencies, the U.S.

updated routinely based on new scientific information. Recently, dietary reference intakes (DRIs) were established by the Institute of Medicine's Food and Nutrition Board to recommend how much of various nutrients individuals and groups of people should be consuming, not just to avoid deficiency but also to optimize health. Continuing efforts are made to explore the possibility that even higher amounts of certain nutrients may provide additional health benefits. To establish the DRIs, experts in nutrition, dietetics, statistics, nutrition epidemiology, public health, economics, and consumer perceptions reviewed the scientific evidence of safety, efficacy, toxicity, and beneficial properties of vitamins, minerals, and a few non-vitamin/non-mineral substances such as water and fiber. The DRIs are listed in Appendix A.

the average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage and gender
group
the average daily nutrient intake level sufficient to meet the nutrient requirement of nearly all (97-98%) healthy individuals in a particular life stage and gender group
a recommended average daily nutrient intake level based on observed or experimentally determined approximations of estimates of nutrient intake by a group (or groups) of healthy people that are assumed to be adequate; used when an RDA cannot be determined
the highest average daily nutrient intake level likely to pose no risk of adverse health effects to almost all individuals in a particular life stage and gender group; as intake increases above the UL, the potential risk of adverse health effects increases
Adapted from Dietary Reference Intakes, Applications in Dietary Planning, Institute of Medicine, 2003.


there is not enough information to determine an EAR and an RDA, an adequate intake (AI) is established. Many nutrients also have a tolerable upper intake level (UL). The values in Table 4.2 were established to guide the consumption of a complete and nutritious diet. Vitamin and mineral dietary supplements may contain a single nutrient (such as vitamin C) or multiple nutrients (such as B-complex or multivitamins). Doses of vitamins and minerals in dietary supplements vary from levels close to the RDA or AI to several times those levels.
The DRIs are used to provide food-based dietary guidance; they are accompanied by national food guides and dietary guidelines for healthy people and provide a basis for food and dietary supplement labels. Although the DRIs and the accompanying guidelines (such as the Dietary Guidelines for Americans and the Food Guide Pyramid) specify daily goals, health professionals use these tools to help people choose diets that provide the recommended nutrients over time.
Several false assumptions have been made regarding vitamin and mineral dietary supplements. For example, vitamin A deficiency causes decreased night vision and, if very severe, blindness. Treating deficient individuals with vitamin A may indeed improve vision. However, many dietary supplements containing vitamin A and beta-carotene (a precursor to vitamin A) claim to "support good eye health." Some consumers falsely assume that if the deficiency of a vitamin or mineral harms a system or organ, then consuming that vitamin or mineral when the body is not in a deficient state will strengthen that system or organ. Some additional assumptions regarding vitamin and mineral dietary supplements are listed in Table 4.3.
Much of the research on vitamins and minerals has investigated whether dietary supplements are superior to food. According to two recent scientific publications by Dr. Alice H. Lichtenstein and Dr. Robert M. Russell, both from the Human Nutrition Research Center on Aging at Tufts University, the answer is no. However, most experts do agree that further research is worth pursuing.