Selenium in the thyroid: physiology and pathology

Selenium (Se) is a trace element that plays a criti- cal role in several processes for human health. The thyroid is the organ with the highest Se con- tent per gram of tissue; in thyroid follicular cells, Se acts as antioxidant by contrasting the produc- tion of the reactive oxygen species that are gener- ated during thyroid hormones biosynthesis. In ad- dition, Se is part of the active site of the deoidinas- es, the enzymes responsible for thyroid hormones activation and inactivation. Herein, the effects of Se supplementation in pa- tients with thyroid related disorders have been re- viewed on the basis of the studies published on this issue.