Copper is required in the body in enzymes associated with oxygen and electron transport. It seems as if nature has chosen copper for this role as it is easy to reduce it from Cu 2+ to Cu + and then to oxidise it again from Cu + to Cu 2+.

Because of this, it is needed as an essential trace element. In other words, it is essential but only needed in very small quantities (around 3mg per day) 1. Good sources of copper in the diet include nuts, sunflower seeds, avocados and olives.

Copper metal does have interesting antibacterial properties (much like silver). This is part of the Oligodynamnic effect and the mechanism for action is still unknown.

A deficiency of copper can lead to anemia like symptoms.

1 Source taken form