Nutritional deficiency can develop as a
result of an inadequate intake, poor absorption, illness, alcohol excess &
other factors
In the UK nutrient intake requirements are
given in:
Dietary
Reference Values for Food Energy and Nutrients for the United Kingdom (1991 TSO)
The report defines The Lower Reference
Nutrient Intake, LRNI,
for protein or a vitamin or mineral as an amount of the nutrient that is enough for only a few people
in a group who have
low needs.
In practice this means that if the percentage
of a population with
an intake below the LRNI for a particular nutrient exceeds 3% then it is likely that a percentage of the
population will be deficient
in the nutrient
Also deficiency is likely, but not certain,
if, on testing its blood level is below the lower end of an accepted normal
range.