The hepatic conversion of vitamin D in alcoholics with varying degrees of liver affection.

The seasonal variations in circulating 25-hydroxycholecalciferol (25-HCC) were studied in 102 alcoholics with fatty liver disease without histologic signs of cirrhosis and in 35 patients with alcoholic cirrhosis. The mean levels were compared with those of normal persons. Alcoholics had generally lower 25-HCC values than the controls, particularly in the summer. This was primarily explained by insufficient diet and reduced exposure to sunshine. The ability of the liver to hydroxylate in the 25-position was studied in three groups of alcoholics with 1) fatty liver disease without cirrhosis, 2) compensated cirrhosis, 3) severely incompensated liver cirrhosis. All three groups exhibited a significant increase in serum 25-HCC following the peroral administration of cholecalciferol at a dose of 1 200 U daily for 7 days. Similar rises were seen 7 days after a single injection of 10 000 U cholecalciferol. This indicates a normal intestinal absorption of vitamin D, even in advanced alcoholic liver disease, and is inconsistent with a severely damaged 25-hydroxylation capacity in these patients. Osteomalacia due to impaired liver hydroxylation of vitamin D can hardly explain the increased fracture rate and the decreased bone mass, which have been described in alcoholics.