Department of Defense and the Office of Disease Prevention and Health Promotion, U.S. Department of Health and Human Services.


Dietary Reference Intakes (DRIs) are reference values that can be used for planning and assessing diets for healthy populations and for many other purposes. The DRIs replace the periodic revisions of the Recommended Dietary Allowances (RDAs), which have been published since 1941 by the National Academy of Sciences. DRIs encompass the Estimated Average Requirement (EAR), the Recommended Dietary Allowance (RDA), the Adequate Intake (AI), and the Tolerable Upper Intake Level (UL).

As has been the practice with dietary recommendations in the past from the Food and Nutrition Board (NRC, 1980, 1989a, 1989b) and Health Canada (1990), the DRIs included in this report apply to the healthy general population. In the case of RDAs and AIs, they are nutrient levels that should decrease the risk of developing a condition related to a nutrient and associated with a negative functional outcome. Intake at the level of the RDA or AI would not necessarily be expected to replete individuals previously undernourished, nor would it be adequate for disease states marked by increased requirements. Although at times these reference intakes may serve as the basis for recommendations for these other purposes, each situation calls for adaptation by qualified professionals.

For this report, consideration of the dietary practices associated with intakes of calcium and related nutrients has been limited to observations within U.S. and Canadian populations. The recommendations for the DRIs may not be generalizable globally, especially where food intake and indigent dietary practices may result in very different bioavailability of mineral elements from sources not considered in traditional diets of Canadians and Americans.

Estimated Average2 Requirement

The Estimated Average Requirement (EAR) is the nutrient intake value that is estimated to meet the requirement defined by a specified indicator of adequacy in 50 percent of the individuals in a life stage


It is recognized that the definition of EAR implies a median as opposed to a mean or average. The median and average would be the same if the distribution of requirements followed a symmetrical distribution, and would diverge as a distribution became skewed. Three considerations prompted the choice of the term estimated average requirement: (1) data are rarely adequate to determine the distribution of requirements, (2) precedent has been set by other countries that have used the same term for reference values similarly derived (COMA, 1991), and (3) the impreciseness of the data evaluated makes the determination of a statistically reliable median extremely unlikely.

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement