title: Vitamin A and zinc metabolism in alcoholism.
abstract: Vitamin A and zinc metabolism are affected both by ethanol and by hepatic cirrhosis. Ethanol causes abnormal dark adaptation by acting as a competitive inhibitor with retinol for alcohol dehydrogenase in the eye. In animals oral ethanol intake results in increased losses of zinc by the urinary and fecal routes. Vitamin A malnutrition in cirrhotics may be caused by poor diet, malabsorption, decreased hepatic vitamin A uptake, and decreased hepatic storage capacity for vitamin A. In some cirrhotic patients zinc deficiency and or protein deficiency may limit the ability to respond to vitamin A. Combined vitamin A and zinc deficiencies are common in cirrhotics and either may result in abnormal dark adaptation or impaired taste and smell. The interaction of these two micro-nutrients must be kept in mind by the clinician caring for alcoholic or alcoholic cirrhotic patients.
mesh_terms: D000437:Alcoholism / Q000378:metabolism*; D000818:Animals; D003623:Dark Adaptation / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology; D006801:Humans; D008099:Liver / Q000378:metabolism; D008104:Liver Cirrhosis, Alcoholic / Q000378:metabolism; D008286:Malabsorption Syndromes / Q000378:metabolism; D012903:Smell / Q000187:drug effects; D013652:Taste Threshold / Q000187:drug effects; D014801:Vitamin A / Q000378:metabolism* / Q000627:therapeutic use; D014802:Vitamin A Deficiency / Q000209:etiology; D015032:Zinc / Q000172:deficiency / Q000378:metabolism* / Q000627:therapeutic use
chemical_list: D014801:Vitamin A; D000431:Ethanol; D015032:Zinc