nutritional disorders
Selenium Deficiency
Introduction
Selenium(Se) is a part of the enzyme glutathione peroxidase, which metabolizes hydroperoxides formed from polyunsaturated fatty acids.Seleniumis also a part of the enzymes that deiodinate thyroid hormones. Generally,seleniumacts as an antioxidant that works withvitamin E. (See also Overview of Minerals .) supplements did not prevent future colorectal adenomas in patients who had colorectal adenomas removed ( General references ), and overall, no evidence suggests that Plasma levels ofseleniumvary from 8 to 25 mcg/dL (0.1 to 0.3 micromoles/L), depending onseleniumintake. Seleniumdeficiency is rare, even in New Zealand and Finland, whereseleniumintake is 30 to 50 mcg/day, compared with 100 to 250 mcg/day in the US and Canada. In certain areas of China, where intake averages 10 to 15 mcg/day,seleniumdeficiency predisposes patients to Keshan disease, an endemic viral cardiomyopathy affecting primarily children and young women. This cardiomyopathy can be prevented but not cured by sodium selenite supplements of 50 mcg/day orally. Patients receiving long-term total parenteral nutrition have developedseleniumdeficiency with muscle pain and tenderness that responded to a selenomethionine supplement. In Siberian Russia and China, growing children withseleniumdeficiency may develop chronic osteoarthropathy (Kashin-Beck disease). deficiency may contribute synergistically with iodine deficiency to the development of goiter and Hypothyroidism ( Diagnosisofseleniumdeficiency is made clinically or sometimes by measuring glutathione peroxidase activity or plasmaselenium, but neither of these tests is readily available. Treatmentofseleniumdeficiency consists of sodium selenite 100 mcg/day orally. 