Dietary Reference Intakes (DRIs), developed and published by the Institute of Medicine, provide estimates of vitamin intake recommended for healthy nutrition. The DRIs look beyond deficiency disease and include the role of nutrients and food components in long-term health.
The DRIs consist of four reference intakes:
Recommended Dietary Allowances (RDAs)
Adequate Intake (AI)
Tolerable Upper Intake Levels (ULs)
Estimated Average Requirements (EARs)
The RDAs are the amounts of ingested vitamins needed by a healthy person to meet daily metabolic needs, allow for biologic variation, maintain normal blood serum values, prevent depletion of body stores, and preserve normal body functions. When an RDA cannot be set, an AI is given as a normal value; both are to be used as goals for the patient. Levels are given for each individual vitamin. ULs are the highest amount that can be consumed on a daily basis and not cause side effects.
The EARs are the amount of ingested vitamins needed by 50% of healthy persons in a particular age group.