Information about Selenium
Selenium is present in biologic systems in amino acids, such as selenocysteine and selenomethionine, usually as a part of proteins, which are referred to as selenoproteins. While selenium is present in many important enzyme systems, deficiency of selenium is rare.
Deficiency of Selenium
Keshan disease, an endemic cardiomyopathy affecting children and young women in parts of China, has been linked to selenium deficiency, although other nutritional deficiencies or local factors may also may a role.
Toxicity of Selenium
Excess selenium exposure can cause cirrhosis in laboratory animals, but toxicity in humans has been linked largely to skin, hair and nail changes. An outbreak of possible selenium toxicity due to a nutritional supplement was marked by nausea, diarrhea, irritability, fatigue, neuropathy, hair loss and nail changes, without liver test abnormalities.
Trace Elements in Tissues and Biologic Systems