The best source of copper is oysters. Nuts , dried legumes , cereals, potatoes, vegetables , and meat also contain copper. Little is known about the clinical effects of these marginally adequate intakes, though frank copper deficiency is uncommon. Children with Menkes' disease are unable to absorb copper normally and become severely deficient unless medically treated early in life. Deficiency can also occur in people who supplement with zinc without also increasing copper intake.
Zinc interferes with copper absorption.
2 Health consequences of zinc-induced copper deficiency can be quite serious. In the absence of copper supplementation, vitamin C supplementation has also been reported to mildly impair copper metabolism. Most people consume less than the recommended amount of this mineral. The level at which copper causes problems is unclear. But in combination with zinc , up to 3 mg per day is considered safe.