Xingen Lei

　　College of Agriculture and Life Sciences, Cornell University

　　Selenium is an essential micronutrient required by animals and humans, and has also been considered to be a strong antioxidant and anticancer agent. There are 25 selenium-dependent proteins in the human body. While dietary Se deficiency produces or provokes a number of diseases in both animals and humans, supranutrition of Se or supplementing Se to subjects with adequate and high selenium status has been found to be associated with increased risks of metabolic diseases including type 2 diabetes and pre-mature mortality. This presentation will discuss the potential mechanisms for those paradoxical roles of selenium and selenium-dependent proteins in human and animal nutrition and health.