Selenium is an essential trace mineral needed for a long and healthy life.
It was discovered 200 years ago by the Swedish chemist Jöns Jakob Berzelius and named after the Greek goddess of the moon, Selene.
Today, selenium is known as the reactive atom in the rare amino acid selenocysteine, that forms the central core of important protective selenoenzymes.
However, the dietary intake of selenium is not always sufficient for full selenoenzyme biosynthesis, conferring an increased and avoidable risk for certain diseases.
Clinical research has indicated that a suboptimal selenium status increases the risk for most major diseases including cancer at several sites (colorectal, prostate, liver), autoimmune and metabolic diseases. The evidence for a medical benefit of selenium supplementation to diseased patients is not as well understood as the evidence linking a selenium deficit to disease risks.