Selenium chelated to the amino acid methionine is one of the most natural and readily absorbable forms of selenium. It is a vital trace element which has been shown to be lacking in many diets today due to factors such as intensive farming methods, acid rain and the high consumption of convenience foods. Selenium is a component of the antioxidant enzyme glutathione peroxidase. It has been shown to help detoxify the toxic element cadmium. Selenium is required for the production of prostaglandins. The immune system is thought to be highly dependent upon selenium.