Selenium is a mineral often considered to be one of the four most important nutritional antioxidants. Selenium is needed to make the powerful antioxidant enzyme glutathione peroxidase. Glutathione peroxidase detoxifies products of oxidized fats. Selenium also works synergistically with Vitamin E to improve its function. Men may have a greater need for selenium since half of their bodies’ supply is concentrated in the prostate and seminal ducts located next to this gland.