Antioxidant relationship between selenium-dependent glutathione peroxidase and tocopherol.

Glutathione peroxidase, a selenium-dependent enzyme, and tocopherol interact and may, indeed, compensate for deficiencies of one or the other. Iron-supplemented, "tocopherol-sufficient," low-birth-weight premature infants fed (selenium-poor) formulas rich in polyunsaturated fatty acid (greater than 35% of fat as PUFA) develop severe hemolysis secondary to erythrocyte phosphatidyl ethanolamine loss. By further increasing tocopherol supplementation one can prevent the clinical expression of a relative tocopherol and an absolute selenium--glutathione peroxidase deficiency. Selenium-poor cow's milk preparations containing 12--15% of fat as polyunsaturated fatty acids, trace amounts of iron, and 12--15 mg/liter of tocopherol are sufficient to maintain proper nutrition without risk of increased peroxidation.