Why is selenium so important? As a “trace” mineral selenium (Se) is a vital micronutrient, with multiple roles in the growth and functioning of living cells in higher animals and humans. Selenium forms about 14 mg of the proximate composition of the average human. Adequate selenium nutrition is essential to maintain the body’s antioxidant defense systems and to efficiently utilize energy. Selenium is involved in immune mechanisms, ubiquinone (coenzyme Q10) synthesis, mitochondrial ATP biosynthesis (energy cycle), and in several metabolic processes. Selenium is also required for normal pancreatic function, which is necessary for the digestion and absorption of lipids including Vitamin E. Once believed to be a carcinogen, selenium was recognized as an essential trace nutrient over forty years ago, and has been extensively researched for its health benefits since the 1990s. Selenium is present as selenomethionine in wheat and other cereals, which therefore represents the major food form of selenium. If ingested in this form, selenium is readily incorporated into selenoproteins in animals and humans.