Method
How to read a reference value
Five values describe one population — not one person. Here is what they mean.
EAR
Average requirement
Meets the needs of exactly half the healthy people in a group. The starting point for further calculations.
RDA / PRI
Recommended intake
EAR plus a margin. Covers 97.5% of the population — a target for planning diets, not for judging one person.
AI
Adequate intake
Used when data do not allow an EAR. Based on observed intake in healthy populations — with greater uncertainty.
UL
Tolerable upper level
The highest steady intake that does not raise the risk of harm in 97.5% of the population. A response to fortification and supplementation.
CDRR / PI-NCD
Chronic-disease prevention
The newest layer: thresholds tied to reducing risk, not to preventing deficiency.