What Is Selenium?

Selenium is one of the trace elements needed by the body in very small amounts. Selenium is used as a component of proteins called selenoproteins, which are important antioxidant enzymes. Selenoproteins, like other anti-oxidants, mop up free radicals and help prevent them damaging cells. Free radicals are natural by-products of oxygen metabolism that may contribute to the development of chronic diseases such as cancer and heart disease. Other selenoproteins help regulate thyroid function and play a role in the immune system.

The selenium that the body needs are obtained from the diet and, as selenium is needed in such small amounts, most people manage to get enough from the plant based foods that they eat. The content of selenium in a food depends on the selenium content of the soil where the plants were grown. Soils in some parts of China and Russia have very low amounts of selenium. Selenium deficiency is often reported in those regions because most food in those areas is grown and eaten locally.