ABSTRACT
The importance of selenium in human nutrition was established with the recognition of its association with two diseases that occur in China: Keshan disease and Kaschin-Beck disease. Selenium deficiency has been reported in patients on total parenteral nutrition. Erythrocyte glutathione peroxidase activity has been considered a functional index of long-term selenium status. The use of plasma and erythrocyte glutathione peroxidase activity measurements for assessing selenium status have summarized by a number of investigators. Serum or plasma selenium concentrations may be a more sensitive indicator of selenium status than whole blood selenium concentrations. Selenium toxicity results in loss of hair and nails, accompanied by lesions of the skin and changes in the nervous system. Plasma or serum selenium concentrations can serve as an indicator of selenium intakes while erythrocyte concentrations can serve as indicators of long-term selenium intakes reflecting the 120-day lifespace of the erythrocytes.
