GLOSSARY

Nutrient Requirement is the amount of a nutrient needed to maintain specified body functions and avoid inadequate supply. It is defined in relation to a person, life stage and conditions. A recommendation for a population is not necessarily a direct measurement of an individual's requirement.

Dietary reference values are developed for defined healthy population groups and are not identical to one person's exact requirement. Average requirement, population reference intake, and adequate intake serve different purposes. Interpretation depends on age, physiological status, and the reference method.

A requirement cannot generally be established completely from one meal or one laboratory value. A useful estimate combines habitual intake, individual characteristics, and activity conditions. Reference figures are a starting point; illness may require a specific assessment.

For example, the protein needs of an athlete in training are not assumed to match those of a sedentary person of the same body mass. More training does not justify unlimited increases in every vitamin. Requirement, measured intake and a recommended target are distinct concepts that need matching units and time periods for comparison.