The DRI includes four subcategories, as follows:

RDA/Recommended Dietary Allowance - This is not a goal for assessing a diet, but rather for intake, and is the daily avg. intake level required to meet the needs of ninety-seven to ninety-eight percent of healthy people in any given gender group or life stage.

Adequate Intake Level/AI - Based on experimentally determined or observed estimates of the vitamin intake of healthy people that is assumed to be adequate. Used when EAR cannot be determined.

Tolerable Upper Intake Level (UI) - As the name suggests, this is the approximated level at which a micronutrient can be ingested while bearing no ill effects on the body. So, as intake increases above this level, the potential risks increase as well.

Estimated Adequate Intake/EAR - Estimated to meet the needs of fifty percent of individuals at a particular life stage or in a particular gender group. It is believed to be the most accurate depiction of need - not including lactating/pregnant women or children under 4 years of age.

It is important to note before closing that the RDA & AI may not be adequate for people recovering from deficiencies, or for those in a diseased or compromised state. They are used, rather, as a tool for planning and assessing a population's healthy diet.

If you enjoyed this article and would like to know more, look for future articles on the requirements and sources of each micronutrient in detail, or follow the link for archives. Thank you!