The effects of daily 0.5 g vitamin C on plasma urea nitrogen, uric acid, cholesterol and triglyceride levels were recorded over a period of one month. There was a significant reduction in plasma cholesterol level (P < 0.05). There was no significant effect of vitamin C on plasma urea nitrogen, uric acid and triglyceride levels (P > 0.05). It was a placebo-controlled trial. The research and control groups were formed of 105 and 47 volunteer university students, respectively. In these groups the mean ages were 20 +/- 0.33 (mean +/- S.E.M.) and 20 +/- 0.49 years, respectively. Mean body mass indices were 22.2 +/- 0.13 and 22.3 +/- 0.19 kg/m2, respectively.