Zinc supplementation of maintenance hemodialysis patients: Effect on serum lipid and copper concentration

The effect of zinc supplementation on serum copper, total cholesterol, HDL, HDL$sb2$ and LDL + VLDL cholesterol was studied using a population of maintenance hemodialysis patients. In a double-blind study, 28 subjects were randomly assigned to either an experimental or control group. Subjects in the experimental group received a supplement of 50 mg of elemental zinc/day for 90 days. A serum sample was obtained from each subject at day 0, 40 and 90 of the study. For all subjects, serum zinc concentration was below normal. Serum zinc concentrations of the zinc supplemented group increased significantly (p $<$ 0.05) at day 40 and 90. Serum copper unexpectedly increased in the zinc supplemented group (p $<$ 0.05). At the onset of the study, serum lipid concentrations were depressed in the subjects. Serum zinc concentration was positively correlated with serum cholesterol (r = 0.63, p $<$ 0.05) and VLDL + LDL (r = 0.62, p $<$ 0.03) from day 0 to day 90 of the study. The elevation in serum cholesterol and VLDL + LDL may indicate that the subjects had altered lipid metabolism due to a marginal zinc status. No changes in HDL or HDL$sb2$ concentrations were observed.