Introduction to dietary reference intakes.

Dietary Reference Intakes (DRIs) are nutrient reference standards used for planning and assessing the diets of apparently healthy Canadians and Americans. The development of DRIs reflects a joint initiative by the United States and Canada to update, expand on, and replace the former Recommended Nutrient Intakes for Canadians and Recommended Dietary Allowances for Americans. DRIs include the Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), Adequate Intake (AI), and Tolerable Upper Intake Level (UL). The EAR is the average daily intake level that meets the requirement of 50% of healthy individuals in a life stage and gender group, whereas the RDA is set at a level that will meet the requirements of almost all (97%-98%) individuals in that life stage and gender group. An AI is a recommended intake level that is thought to meet the needs of almost all healthy individuals, and is set when there are insufficient data to establish an EAR (and therefore an RDA). The UL represents a threshold above which adverse effects of excessive intake may increase. In addition to these DRIs, macro nutrients have an Acceptable Macro nutrient Distribution Range (AMDR) and, for energy, an Estimated Energy Requirement (EER) is described.