These values are used in assessing the diets of groups of people. There are four categories of dietary reference value:
Estimated Average Requirement (EAR)
The estimated average requirement for food energy or a nutrient. Many people will need more than this value and many will need less.
Reference Nutrient Intake (RNI)
The amount of a nutrient that is enough for almost every individual - even someone with high needs for that nutrient.
Lower Reference Nutrient Intake (LRNI)
The amount of a nutrient which is enough for only a small number of people with low needs. People regularly eating less than the LRNI are likely to be deficient.
Safe Intake or Desirable Upper Level
Where there is not enough information to estimate requirements of a nutrient, a safe intake is the amount of the nutrient which is judged adequate for almost everyone's needs, but small enough not to cause undesirable effects.