Copper is important for bone formation and maintenance, is necessary for the absorption and utilization of iron, and is required (in conjunction with zinc and vitamin C) for connective tissue formation. It is necessary for the production of RNA, phospholipids and adenosine triphosphate (ATP, the basic energy molecule of all cells) and for protein metabolism. Copper is required by the immune system to support the production of some cytokines by T cells and regulate T cell proliferation (cell division), and dietary copper is important in resistance to infection.
Excellent sources of copper include oysters and other shellfish, legumes, nuts, organ meat, and mushrooms.
Chromium