reference intakes

reference intakes (of nutrients) Amounts of nutrients greater than the requirements of almost all members of the population, determined on the basis of the average requirement plus twice the standard deviation, to allow for individual variation in requirements and thus cover the theoretical needs of 97.5% of the population.  Reference intakes for energy are based on the average requirement, without the allowance for individual variation. Used for planning institutional catering and assessing the adequacy of diets of groups of people, but not strictly applicable to individuals. Tables of reference intakes published by different national and international authorities differ because of differences in the interpretation of the available data.

Variously called, in different countries and by different expert committees: RDA, the Recommended Daily (or Dietary) Amount (or Allowance); RDI, Recommended Daily (or Dietary) Intake; RNI, Reference Nutrient Intake; PRI, Population Reference Intake; safe allowances. See appendices IV–VII.

Levels of intake below that at which health and metabolic integrity are likely to be maintained are generally taken as the average requirement minus twice the standard deviation. Variously known as Minimum Safe Intake (MSI), Lower Reference Nutrient Intake (LRNI), and Lowest Threshold Intake.