RDA
A set of reference levels for nutrient intakes. In the USA, the RDA is an estimate of the average safe amount of nutrients and energy needed to maintain good health in a person who is already healthy. RDAs are adjusted for men, women, and children, and for different age groups, as well as for pregnant women. The further below the RDA intake is, the greater the risk of deficiency; the further above the RDA, the greater the risk of toxic effects. RDAs were revised in 1989 by a panel of nutrition specialists. RDAs were based on their expert opinion rather than proven fact. RDAs form the basis of Reference Daily Intakes (RDIs). The Nutrition and Labeling Education Act of 1990 mandates that nearly all foods in the USA should have RDIs on their labels.
Until 1991, RDAs were also published in Britain when they were replaced with Dietary Reference Values. There were considerable differences between the British RDAs and those set in the USA. The standards have been used on both sides of the Atlantic by individuals to check the nutritional adequacy of their diets. However, this is not the intended use of RDAs. They were devised as estimates of average safe levels for population groups. See also Dietary Reference Values.
