Copper

What it does

Copper is a trace mineral that acts as an essential partner for a range of enzymes, several of which handle jobs no other mineral can do. It is needed to help the body use iron properly — copper-containing enzymes load iron onto its transport protein — so a copper shortage can cause an anaemia that looks like iron deficiency but does not respond to iron alone. Copper and iron metabolism are tightly linked.

Copper enzymes are also central to producing energy in the cell's mitochondria, to building the connective tissue that gives strength to blood vessels, skin and bone, and to protecting cells from oxidative damage. It plays a part in the nervous system too, helping to make neurotransmitters and to maintain the protective myelin around nerves, as well as contributing to the pigment (melanin) that colours skin and hair.

Copper is found in shellfish, liver, nuts, seeds, wholegrains and dark chocolate, and most varied diets supply enough. The body regulates copper carefully, and balance with zinc matters — very high zinc intakes, usually from over-supplementing, can block copper absorption and eventually cause a deficiency. Both inherited disorders of too much and too little copper exist, underlining how tightly the body normally controls it.