ABSTRACT
The essential role of selenium in human health has been demonstrated recently. Dietary selenium supplementation has been shown to prevent a congestive cardiomyopathy in China (Keshan disease). 1 In patients with prolonged total parenteral nutrition, selenium supplementation prevented a muscular dystrophy. 2 The biochemical function of selenium is in part related to glutathione peroxidase (GSH-Px), an intracellular enzyme that catalyzes the oxidation of reduced glutathione by peroxides to form oxidized glutathione and water. Each of the four units of GSH-Px needs selenocysteine, and an adequate plasma selenium concentration is requested for a correct function of GSH-Px. 3 Selenium influences the functions of the immune system in animals, and immunologic abnormalities such as impaired cytotoxicity or phagocytosis or poor response to vaccines occur in selenium-deficient animals. 4 , 5 , 6 An antiviral effect of selenium has also been suggested: addition of sodium selenite to table salt has significantly lowered the hepatitis B infection rate. 7 A deficiency in selenium is rare in healthy subjects although dietary selenium intakes vary a lot from one country to another because of differences in selenium concentration in food and soil (the highest selenium concentrations are found in fishes). 8 Selenium deficiencies may occur in pathological conditions such as malnutrition or malabsorption. 2 , 9 , 10 More than half of all AIDS patients have wasting defined as a 10% body weight loss, and malabsorption is often demonstrated in HIV-positive patients 11 , 12 so that several authors investigated plasma selenium concentration in HIV-positive subjects.
