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If the estimated coefficient of variation is 15 percent, the formula would be

RDA = 1.3 × EAR.

If the nutrient requirement is known to be skewed for a population, other approaches are used to find the ninety-seventh to ninety-eighth percentile to set the RDA.

The RDA for a nutrient is a value to be used as a goal for dietary intake by healthy individuals. As discussed in Chapter 13 of the report, the RDA is not intended to be used to assess the diets of either individuals or groups or to plan diets for groups.

Adequate Intakes

The Adequate Intake (AI) is set instead of an RDA if sufficient scientific evidence is not available for calculating an EAR. The AI is based on observed or experimentally determined estimates of nutrient intake by a group (or groups) of healthy people. For example, the AI for young infants, for whom human milk is the recommended sole source of food for the first 4 to 6 months, is based on the daily mean nutrient intake supplied by human milk for healthy, full-term infants who are exclusively breastfed. The main intended use of the AI is as a goal for the nutrient intake of individuals. Other possible uses of AIs will be considered by another expert group.

Tolerable Upper Intake Levels


ULs are useful because of the increased interest in and availability of fortified foods and the increased use of dietary supplements. ULs are based on total intake of a nutrient from food, water, and supplements if adverse effects have been associated with total intake. How-

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