A brief history of selenium research: From alkali disease to prostate cancer (from poison to prevention)

The trace element selenium has followed an unusual route on its way to becoming recognized as an essential nutrient. First feared as a plant toxin and later impugned as a suspected carcinogen, it has been shown to be required in the diets of animals and humans, in small quantities, and has been recognized as an effective anticarcinogen. Areas of selenium deficiency have been mapped, worldwide, and in them selenium supplementation has become an accepted practice. A number of means of administering selenium