Affiliation:
1. Faculty of Health Sciences, Bandırma Onyedi Eylül University, Turkey
Abstract
Selenium is an element that is essential in small amounts for the organism's functioning, and its deficiency or excess causes negative health outcomes. Selenium is obtained from dietary sources and performs various physiological functions in the body, especially as selenoproteins. Selenium supports antioxidant defense systems and plays a crucial role in the immune system. It also is involved in the metabolism of thyroid hormones and is an essential element for fertility/reproductive health. Despite its importance, selenium deficiency is still prevalent in the world. The endemic diseases that occur in selenium deficiency are Keshan disease and Kashin-Beck disease. Apart from these diseases, selenium deficiency has been associated with many chronic diseases such as cardiovascular diseases, thyroid diseases, and cancer. This chapter provides insights into the functions of selenium in the organism, its dietary sources, the diseases caused by its deficiency, and its management.