The relationship among impaired selenium status, lipid peroxidation, and liver function was examined in 19 hospitalized patients with severe alcoholic cirrhosis. Plasma selenium was found to be significantly lower (mean +/- SD: 54 +/- 13 micrograms/L) than in healthy controls (83 +/- 11 micrograms/L) and plasma malondialdehyde, assessed as thiobarbituric acid reactants, which reflects lipid peroxidation, was increased (2.0 +/- 1.2 mumol/L vs < 1.2 mumol/L in controls). The mean 14C aminopyrine breath test, an indicator of liver function, was lower than normal (2.7 +/- 1.9 vs 6.3 +/- 0.9% in controls) and found to be significantly correlated with plasma selenium (r = 0.59, p < 0.05). A prospective, randomized selenium supplementation trial was conducted in a group of 16 patients who received either daily 100 micrograms selenium as enriched yeast during 4 mo or a placebo. Among the 10 patients who completed the study, plasma selenium significantly increased in the supplemented group (n = 4; before: 58 +/- 10 micrograms/L, and after 101 +/- 12 micrograms/L, p < 0.01) contrary to the placebo group (n = 6, before: 47 +/- 10 micrograms/L, after: 57 +/- 9 micrograms/L, n.s.). 14C aminopyrine breath test improved in three out of four selenium-supplemented patients and in three out of six placebo patients, but the small number of patients did not allow statistical evaluation. These results demonstrate that low selenium status in alcoholic cirrhosis is correlated to liver function and could be improved by supplementation.