Glossary

RDA (Recommended Dietary Allowance)

The RDA is the daily intake level in the US and Canada DRI system that meets the needs of 97.5% of healthy people.

Written by Metehan Yılmaz
In this guide

The RDA (Recommended Dietary Allowance) is, in the Dietary Reference Intakes (DRI) system of the US and Canada, the average daily intake level sufficient to meet the nutrient requirement of about 97.5% of healthy individuals in a given life stage and sex group. It is set two standard deviations above the EAR value, which shows the average requirement, and is used in planning an individual’s intake to keep the probability of inadequacy low; it is not used for groups. [1]

In the same system, the EAR is the average intake that meets the requirement of half; the AI (Adequate Intake) is given, when the EAR and RDA cannot be determined, based on observed or experimentally determined intake levels; and the UL is the upper intake level (Tolerable upper intake level). [1]

The equivalent in Europe

For the same purpose, EFSA uses, under the umbrella of Dietary Reference Values (DRV), the Population Reference Intake (PRI), Average Requirement (AR), Adequate Intake (AI) and reference intake ranges for macronutrients; ULs are also included in this framework. [2] Because terms and values can vary from institution to institution, which institution a value comes from is always stated.

Its limit

The RDA is not a target or a mandatory amount. By definition it is chosen above the average requirement; therefore an intake below the RDA does not by itself show deficiency, and it does not follow from this definition that an intake exceeding the RDA provides additional benefit. For values by nutrient, see the What are vitamins? and What should vitamin D be? pages.

Sources

  1. Murphy SP et al. — History of Nutrition: The Long Road Leading to the Dietary Reference Intakes for the United States and Canada (Adv Nutr), Tablo 1 (2016)
  2. EFSA — Dietary Reference Values for nutrients: Summary report (EFSA Supporting Publications) (2017)

Updated

This content is for information only and is not medical advice. It does not recommend doses, products or vendors. Talk to your clinician before making any health decision.