Safety limits for nutrients.
Hathcock JN
J Nutr 1996 Sep 126:9 Suppl 2386S-2389S
Abstract
The occurrence of adverse health effects from ingestion of any
substance depends on its inherent toxic potential, the amount of
intake, and the biological characteristics of the exposed
individual. A safe intake is one that provides an acceptable
margin of safety
below the intake that carries risk of adverse effects. If
appropriate data are available, applying fixed safety factors,
systematically
varying safety factors or using other methods to identify
reasonable limits for safe intakes. A crucial factor in
understanding the
margin of safety that a particular intake is likely to provide is
the adequacy of the data to estimate the likely frequency of the
adverse
response among persons with that intake. For a few nutrients
there are sufficient numbers of reports of adverse effects over a
sufficiently wide range of exposures to allow estimation of
lowest adverse effect levels; for other nutrients the reports of
adverse
effects are too infrequent or inconsistent to support estimations
that are meaningful.