Vitamin A in dietary supplements and fortified foods: too much of a good thing?

Vitamin A consumption by many Americans is quite high, in part because of the consumption of fortified foods and the use of vitamin supplements. Most multivitamin supplements provide two or more times the recommended dietary allowance (RDA) for vitamin A because the daily value (DV) is based on 1968 and not current RDAs. Consumption of just one multivitamin often provides excessive vitamin A, the majority of it as preformed vitamin A esters. Given recent epidemiologic evidence that suggests a link between chronic intakes of vitamin A that exceed the RDA and hip fractures, it may be time to reexamine food and supplement fortification policies and to discontinue the clinical practice of prescribing two multivitamins to the elderly and other patients whose needs for certain micronutrients are high.