Function:
Copper is necessary for the proper development of connective tissue, nerve coverings, and skin pigment. It is necessary for oxidation and absorption of iron and vitamin C. Copper also acts as a catalyst in the formation of hemoglobin, the oxygen-carrying blood molecule.

Recommended Dietary Allowance:
The RDA is 900 mcg a day for both men and women.

Deficiency:
Copper deficiency is rare, observed in a genetic disorder and in infants fed only cows milk.

Sources:
Copper is widely distributed in foods such as organ meats, seafood, nuts, and seeds. Some foods that are consumed in substantial amounts, such as milk, tea, chicken, and potatoes, also contain the nutrient, but at lower levels.

Toxicity and UL:
Copper excess occurs in a genetic disease (Wilson's Disease) in which excess copper is stored in the liver, kidney, and brain producing toxicity.

To protect against possible liver damage, the UL was set at 10 mg per day.

Recommendation:
Copper supplementation is not necessary but can safely be taken at a level not to exceed the RDA.

For more information:
http://osu.orst.edu/dept/lpi/infocenter/minerals/copper/