Lack of effects of copper gluconate supplementation

A double-blind study was done giving 10 mg of copper/day as copper gluconate or placebo capsules for 12 wk. The seven subjects receiving copper gluconate had no change in the level of copper in the serum, urine, or hair. There was also no change in the levels of zinc or magnesium. There was also no significant change in levels of hematocrit, triglyceride, SGOT, GGT, LDH, cholesterol, or alkaline phosphatase. The side effects of nausea, diarrhea, and heartburn were the same in the subjects receiving copper gluconate and subjects receiving placebo capsules.