ABSTRACT
Erythrocyte zinc is generally rated as being of minimal value in assessing zinc nutriture. One limitation to the usefulness of erythrocyte zinc is its relatively slow response to changes in zinc status measured by other techniques. Another limitation is the lack of standardization of analytical techniques, which has contributed to irreproducibility of results. The available body fluids, plasma or serum, milk, urine, saliva, and semen are of limited usefulness in the assessment of zinc status. A change in the level of zinc in plasma may reflect a clinically significant change in zinc status, but it may also reflect a physiological change, such as during pregnancy or acute infection. A number of problems still remain in the search for a suitable body fluid or tissue from which to reliably assess zinc nutriture. The method of assessing zinc nutriture that is considered most reliable is that of clinical evaluation of the individual's response to zinc supplementation.
