| Please note: This document references the Food Guide Pyramid, which was updated in April 2005 by the United States Department of Agriculture and is now the MyPyramid Food Guidance System. Please check back for an updated version of this document. In the meantime, visit http://www.mypyramid.gov for more information. |
What are Dietary Reference Intakes?For more than 50 years, the Food and Nutrition Board (FNB) of the National Academy of Sciences has been reviewing nutrition research and defining nutrient requirements for healthy people. Until recently, one set of nutrient intake levels reigned supreme: the Recommended Dietary Allowances (RDAs). But now the FNB has updated its approach and is developing new recommendations. In addition to the RDAs, three new values have been created: the Estimated Average Requirement (EAR), the Adequate Intake (AI) , and the Tolerable Upper Intake Level (UL) . All four values are collectively known as Dietary Reference Intakes or DRIs.
How are DRIs determined?
The FNB convenes various panels of expert nutrition scientists who thoroughly review all available scientific data for each nutrient or component and carefully determine the recommendations. Since 1997, DRIs have been determined for thirty-two nutrients. Values are expected to be set for twelve more nutrients, including water, and components including alcohol and phytochemicals.
What is a Recommended Dietary Allowance (RDA)?
The RDA is the average daily intake that will meet the nutrient requirement of nearly all healthy people in a specific age and gender category. In the past, the RDA of most nutrients represented the levels needed to prevent deficiency diseases such as rickets (lack of vitamin D) or scurvy (lack of vitamin C). Now, an RDA also includes the goal of preventing chronic diseases such as osteoporosis and heart disease, where applicable. The RDA of a nutrient is computed using the Estimated Average Intake (EAR), which represents the average daily nutrient intake level estimated to meet the requirement of half of the healthy individuals in a particular life stage and gender group.
What is an Adequate Intake (AI)?
An AI is set when there is not enough scientific evidence to determine the RDA. The AI is based on estimating the amount of a nutrient eaten by a group of healthy people and assuming that the amount they consume is adequate to promote health. The AI is set at a level to meet or exceed the needs of virtually all people in a specific age and gender category.
What is a Tolerable Upper Intake Level (UL)?
A UL is the highest amount of a nutrient that can be safely eaten on a continual basis and will not cause an adverse effect for most healthy people. The adverse health effect used to determine a UL will vary from nutrient to nutrient. For instance, the adverse effect identified for niacin is flushing, or redness of the face, and niacin’s UL only applies to the form of niacin used in supplements and fortified foods. Many people can safely consume the UL amount, but should use discretion.
Are ULs set for all nutrients?
ULs are set when there is a pool of strong scientific data. If the scientific data are limited (i.e., there are not enough studies or the studies are not conclusive), then a UL will not be set. Therefore, it’s important to understand that if there is no UL for a nutrient it may mean that it is safe at all levels or that it is best to be careful about eating levels above the RDA or AI.
How are the DRIs used?
For the most part, the DRI values are used by scientists and nutritionists who work in research or academic settings and by nutritionists who develop menus that must meet certain nutritional requirements (elderly feeding programs, prisons, military feeding programs). So far, the DRI values have not been incorporated into consumer information such as food labels or the Food Guide Pyramid.
Will DRIs be used in food labeling?
A committee of the Food and Nutrition Board is currently investigating a model to incorporate the DRI values into the food label. Once the committee’s work is completed, the Food and Drug Administration may propose changes to food labeling laws.
