ABSTRACT
Selenium (Se), which is named after the Greek goddess of the moon (Selene), is located in the same group of VIb as oxygen and sulfur in the periodic table. Together with arsenic, Se is categorized as a metalloid, an intermediate of metals and nonmetals. In the scene of trace element research, Se first appeared as a poisonous element causing “blind staggers” and “alkali disease” in stock animals in the 1930s. Since 1957, however, when the role of Se for preventing hepatic necrosis caused by vitamin E deficiency was reported (1), physiological functions of Se have been investigated extensively. The findings by two groups in 1973 (2, 3) that Se constitutes an active site of glutathione peroxidase (GPx) have provided a logical basis for the role of Se as an antioxidative essential element. Furthermore, the findings that the mortality and morbidity of Keshan disease, an endemic cardiomyopathy in China, were dramatically reduced by supplementation with sodium selenite have promoted the studies on nutritional roles of Se in human health and disease.
