International perspective: basis, need, and application of recommended dietary allowances.

Abstract

The RDAs emerged in World War II to thwart existing nutrient deficiencies. The RDAs are estimates of need based on the data available. There has been remarkably little change in RDA values. The ongoing revision of the RDAs will introduce new terminology and attempt to recommend values that not only ensure the prevention of nutrient deficiency but that would thwart the more prevalent chronic degenerative diseases as well and recommend upper safe limits for RDA nutrients. The overall goal is to provide estimates of dietary allowances that are intended to avoid preventable illness, including freedom from outright clinical deficiency of truly essential nutrients.