Selenium is an essential cofactor for glutathione peroxidases, which maintain antioxidant defenses by inactivating hydrogen peroxide.¹ Selenium also supports iodine metabolism to maintain healthy thyroid hormone production.¹ This trace mineral is also involved in the production of certain prostaglandins that promote healthy blood flow.² Selenium may also support healthy growth and fertility, as indicated in a research study using a combination of selenomethionine and vitamin E.³ Selenium also provides support for the immune system.⁴ Selenomethionine is an organic form of the mineral that occurs naturally in Brazil nuts and legumes, and consists of selenium bound to the amino acid methionine. During digestion, selenium is released from methionine. Selenium is absorbed primarily in the duodenum and proximal small intestine and transported to tissues via specialized transport proteins.^1‡