This study was designed to examine the hypothesis that dl-alpha-tocopheryl acetate (vitamin E) increases the level of high-density lipoprotein cholesterol (HDLC) with a concomitant decrease of the ratio of total cholesterol/HDLC and a resultant amelioration of the coronary risk profile. Vitamin E (500 IU/day) or placebo were administered under double-blind randomized allocation to 69 hypercholesterolemic patients for 3 months. Sixty patients completed the study (30 in the active treatment group and 30 in the placebo group). Vitamin E raised the mean level of HDLC from 1.39 +/- 0.38 (SD) to 1.58 +/- 0.41 mmol, a 13.6% increase. This increase significantly (P less than 0.05) exceeded a parallel smaller increase of only 0.05 mmol (3.8%) in the placebo group. As total cholesterol (TC) declined by similar proportions in the vitamin E (7.8%) and placebo (9.4%) groups, a concomitant reduction of 23% in the TC/HDLC ratio was achieved in the vitamin E group, significantly exceeding a 9.1% reduction under placebo. Significant beneficial effects were noted on apolipoprotein (Apo) A (which rose) and Apo B (which declined). An increase of Apo A/Apo B ratio by 17.9% was observed only in the vitamin E group. These results suggest that the oral administration of vitamin E (500 IU/day) is beneficial in hyperlipoproteinemia and offers a potential tool for treating the increased coronary heart disease risk.