Selenium increases the levels of glutathione peroxidase, which helps to reduce lipoperoxidation. Selenium may improve energy levels and help in the process of aging by attacking free radicals.

Selenium is needed for pancreatic function and tissue elasticity. It is essential for reproduction; some studies have shown that selenium deficiency results in infertility. Sperm cells contain high amounts of selenium. Considerable amounts are lost during sexual intercourse; for this reason, selenium necessity is higher in men than women.