Effect of zinc supplementation on copper status in adult man.

The effects of zinc supplementation on the copper status of healthy adult men, as assessed by the activities of the copper-metalloenzymes, plasma ferroxidase (ceruloplasmin), and erythrocyte Cu,Zn-superoxide dismutase, were determined. The subjects were given either two daily doses of 25 mg zinc or placebo for 6 wk. No significant differences in the plasma copper levels or the ferroxidase activities between the supplemented and control groups could be detected at 2, 4, or 6 wk. Plasma zinc increased and erythrocyte Cu,Zn-superoxide dismutase decreased in the supplemented group, the difference between the groups becoming significant at 6 wk (p less than 0.05). This suggested that the zinc supplements decreased the copper status of the experimental group.