RDA (Recommended Dietary Allowance)

What Is the RDA?

The Recommended Dietary Allowance (RDA) is the average daily dietary intake level sufficient to meet the nutrient requirements of nearly all (97–98%) healthy individuals in a specific age and sex group. RDAs are established by the National Academies of Sciences, Engineering, and Medicine (NASEM) through the Dietary Reference Intakes (DRI) framework and are updated periodically as new evidence accumulates.

The RDA is derived from the Estimated Average Requirement (EAR) — the intake level estimated to meet the needs of 50% of healthy individuals — plus two standard deviations, covering the vast majority of the population. If an EAR cannot be established, an Adequate Intake (AI) value is set instead.

RDA Values for Key Nutrients (Adults 19–50)

Understanding RDA in Practice

The RDA is not a minimum threshold or a personal target — it is a population-level statistical construct. An individual who consistently consumes slightly below the RDA for a given nutrient is not necessarily deficient; their personal requirement may be lower than the population average. Conversely, certain populations — pregnant women, older adults, people with malabsorption disorders, and those with limited sun exposure — may have requirements that exceed the standard adult RDA. Clinical assessment of nutritional status should combine dietary intake data with biomarker measurements rather than relying solely on RDA comparisons.