Vitamin A Deficiency

Autor: Sidrys, Linas A., Partamian, Leon G.
Zdroj: Archives of Dermatology; November 1979, Vol. 115 Issue: 11 p1286-1287, 2p
Abstrakt: TO THE EDITOR.— Harry L. Wechsler, MD, recently reported (Archives 115:73-75, 1979) phrynoderma and night-blindness of vitamin A deficiency in a patient who underwent a jejunoileal bypass operation. The 18-year-old woman was then treated with 150,000 units of vitamin A orally for two months until both dermatologic and ophthalmologic symptoms resolved, followed by a maintenance dose of 50,000 units daily.Empiric guidelines for vitamin A replacement in the presence of malabsorption have not been established. The prolonged daily intake of 50,000 IU, even with malabsorption, may possibly cause vitamin A toxicity. The AMA Drug Evaluations (third edition) notes that prolonged daily intake of 7,000 to 10,000 IU by dietary deficient adults generally causes toxic symptoms. Furthermore, the safety of doses exceeding only 6,000 IU daily during pregnancy and lactation has not been verified. In animal experiments, hypervitaminosis A has produced congenital anomalies. In addition, the hepatotoxicity of chronic hypervitaminosis A
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