the report is precise, but should not require extensive background in statistics to be useful.
An important consideration in the application of the DRIs in both assessment and planning is that a nutrient requirement is defined as the lowest continuing intake level of a nutrient that will maintain a defined level of nutriture in an individual. The criterion of nutritional adequacy on which requirements are based differs among nutrients, and may also differ for a given nutrient depending on the life stage of individuals. The criterion used, the rationale for its selection, and any functional indicators are described in depth in each of the nutrient reports in this series (IOM, 1997, 1998b, 2000). The criterion or criteria chosen for a specific nutrient is for the healthy U.S. and Canadian populations and may not be the most appropriate criterion for other populations. This has important implications for those using the DRIs in assessment or planning. For example, agreement between assessment of dietary intake and assessment of nutritional status cannot be expected if the criterion used to determine the requirement and the criterion used in clinical and biochemical examination for other purposes are not the same.
For the DRIs published at the time this report went to press, the requirement for each nutrient is presented as a single reference intake (amount) for various life stage and gender groups rather than as multiple endpoints. This approach differs from that of the joint World Health Organization and Food and Agriculture Organization Expert Consultation on requirements of vitamin A, iron, folate, and vitamin B12 (FAO/WHO, 1988), which recommended both a basal requirement (the amount of nutrient needed to prevent clinically detectable impairment of function) and a normative storage requirement (the amount of nutrient needed to maintain a desirable level in tissues). The single endpoints established for DRIs currently available are more in keeping with a normative storage requirement than a basal requirement.
Dietary Reference Intakes (DRIs) are relatively new to the field of nutrition. The DRIs are a set of at least four nutrient-based reference values that can be used for planning and assessing diets and for many other purposes. They are meant to replace the former Recommended Dietary Allowances (RDAs) in the United States and Recommended Nutrient Intakes (RNIs) in Canada. The DRIs differ from the former RDAs and RNIs in that (1) where specific data on