Copper Copper is a mineral that promotes e.g. normal transport of iron and maintenance of connective tissues. It is also an antioxidant that protects cells from oxidative stress. Copper promotes keeping connective tissue normal normal energy metabolism normal nervous system function normal pigmentation of hair normal transport of iron in the body normal pigmentation of skin normal immune system function the protection of cells from oxidative stress Good sources of copper in food are e.g. liver and internal organs, whole grains, potatoes, nuts, legumes and shellfish.