To study the effect of prolonged ethanol consumption on calcium metabolism and on the prevalence of osteoporosis we examined 38 Finnish noncirrhotic male alcoholics (30-55 years of age) with dietary interviews and biochemical measurements and by measuring the bone mineral content of the forearm using single photon absorptiometry (SPA) and the bone mineral density of the spine, humerus and proximal femur using nonquantified computer tomography (CT) and dual-energy x-ray absorptiometry (DEXA). In comparison two groups of healthy controls were studied. The mean daily dietary intake of calcium was 1.3 g in the patients and 1.2 g in the controls. The dietary intake of vitamin D was equal in the study groups, too. The serum levels of calcium, phosphate and parathyroid hormone did not show any difference between the patients and controls but in the alcoholics the urinary excretion of calcium was reduced by 42% (p less than 0.0001) as compared to the controls. The serum levels of 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and 24,25-dihydroxyvitamin D3 were reduced in the alcoholics by 40% (p less than 0.0001), 23% (p less than 0.01), and 48% (p less than 0.0001), respectively, as compared to the controls. The alcoholic men had normal levels of serum testosterone and they did not have hypercortisolism. The bone mineral content of the dominant forearm measured by SPA was similar in the study groups as were the bone mineral densities (BMD) of the lumbar and humeral areas measured by CT. The BMD at the lumbar, femoral neck, Ward's triangle and trochanter sites measured by DEXA did not differ, either.(ABSTRACT TRUNCATED AT 250 WORDS)