Vitamin Dietary Reference Intakes, Recommended Dietary Allowance

Insufficient vitamin intake will lead to a number of vitamin deficiency diseases. However, high doses of vitamins should be regarded as drugs rather than supplements, which will causes some potential health risks. To keep people informed of the correct nutrition intake, the Food and Nutrition Board of the National Academy of Sciences/National Research Council publishes the Recommended Daily Allowances (RDA) for vitamins and other nutritional supplements based on scientific researches and clinical findings. The amounts of nutrients and calories an individual is recommended to consume daily to maintain good health for the majority of populations.

The Dietary Reference Intakes (DRIs) are a comprehensive set of nutrient reference values for healthy populations that can be used for assessing and planning diets. DRIs replace previously published Recommended Nutrient Intakes (RNIs). Estimated Average Requirement (EAR) is the average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage and gender group. Recommended Dietary Allowance (RDA) is the average daily dietary nutrient intake level sufficient to meet the nutrient require- ment of nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group. Adequate Intake (AI) is the recommended average daily intake level based on observed or experimentally determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate - used when an RDA cannot be determined. Tolerable Upper Intake Level (UL) is the highest average daily intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects may increase.