Evaluation of hair analysis for determination of zinc status using rats

Weanling male and female Sprague-Dawley rats were fed diets of graded levels of dietary zinc from 3 to 68 ppm. The zinc concentrations of hair, bone, and testes reflected the dietary intake by increasing with each increment of dietary zinc. Kidney zinc indicated the state of zinc metabolism by declining on restricted intakes and remaining constant above the requirement level. Plasma and liver zinc concentrations and enzyme activities were not related to dietary intake nor were any significant changes observed with restricted zinc intakes. Hair zinc levels decreased more rapidly with dietary zinc levels below the zinc requirement. Therefore, hair zinc analysis can be used to aid in diagnosis of a deficiency or evaluate dietary intake for the rat but can not be used to assess the state of zinc metabolism.