Copper is an essential trace element present in the diet and in the human body. It is needed to absorb and utilize iron. It is also part of the antioxidant enzyme, superoxide dismutase (SOD). Copper is needed to make adenosine triphosphate (ATP), the energy the body runs on. Synthesis of some hormones requires copper, as does the synthesis of collagen (the "glue" that holds connective tissue together). In addition, the enzyme, tyrosinase, which plays a role in the production of skin pigment, requires copper to function.