Serum copper, zinc, selenium, magnesium, calcium, cholesterol, triglyceride and retinol contents were determined in 11 patients with ulcerative colitis and in 20 healthy volunteers. Lipid and retinol loadings were performed as well. No differences were found in serum copper, zinc, calcium and selenium levels between the groups. Serum magnesium levels were somewhat lower in the patients than in the volunteers. During the period of loading, cholesterol levels did not differ between the two groups at any time. Triglyceride levels except for two persons, were higher in patients. Triglyceride curves showed pathological courses in each case. Retinol concentrations in patients remained below the values observed in volunteers. Data suggest a disturbed utilization of fat and retinol in patients with ulcerative colitis.