Selenium 200 mcg

Until the late 1950s, selenium was thought to be toxic but is now known to be an essential trace mineral. Although it can indeed be toxic at high doses (more than one milligram a day), it is now recognized as an important element of nutrition. Selenium is an important part of the antioxidant enzyme glutathione peroxidase. It helps protect cells against the effects of free radicals that are produced during normal oxygen metabolism.