Copper is an essential trace mineral found in abundance in many food sources, particularly oysters, shellfish, legumes and in tap water due to the use of copper pipes in domestic water supplies. The Recommended Daily Amount (RDA) for copper is 1.2mg for both males and females in the UK.
Copper is required for the conversion of iron into haemoglobin- red blood cells that carry oxygen around the body. It also aids in the formation of bone and red blood cells and works in balance with zinc and vitamin C to form elastin, an important skin protein. It is involved in energy production, the healing process, colouring of the hair and skin and in taste sensation. Copper contributes to the protection of cells from oxidative stress and the normal function of the nervous system and the immune system.
Copper deficiency results in iron deficiency anaemia because copper is required for proper iron absorption and utilization. A deficiency is also associated with poor collagen integrity due to its role in the production of elastin. A deficiency can therefore manifest itself in the rupture of blood vessels, osteoporosis, bone an joint abnormalities. Other symptoms include brain disturbances, low levels of good cholesterol and impaired immunity.
Immunity– It has been shown that moderate and even marginal copper deficiency may be detrimental to activities of the immune system (1). Severe copper deficiencies have been associated with changes to cells in blood, bone marrow, and lymphoid tissues. Copper deficiency has also been shown to suppresses a number of activities of immune cells such as lymphocytes (white blood cells responsible for fighting infection) and phagocytic cells (cells which ingest harmful bacteria) (2). Copper deficiency has been shown to result in low white cell numbers in humans (3), (4). It has also been shown that frequent and severe infections are common in infants with a severe genetic copper deficiency known as Menkes disease (6), (7).
Maintenance of connective tissues-According to the EU Commission, 2012 (2), there is evidence from consensus opinions and reports from authoritative bodies and reviews that demonstrate the role of copper in the formation of elastin and collagen, which constitute the structure of connective tissues. Rodriguez et al., 2008 (8) reports that the symptoms of severe copper deficiency include lack of collagen maturation and defective sheathing of blood vessels, which can result in aneurysms (bulges in the blood vessels which can be fatal if ruptured).
Energy Production– The EU Commission panel, 2012 (2) also recognizes there is an established cause and effect relationship between the dietary intake of copper and normal energy-yielding metabolism. Copper is involved in many oxidative reactions that break down fats in fat tissue to produce energy in the form of ATP.
Nervous system Support– Copper has been shown to contribute to the health of the nervous system. This is because copper is required for the formation and maintenance of myelin- a fatty white substance that surrounds the nerve fibres. Malformations of the myelin sheath have been found in copper-deficient animals (9).
Pigmentation-Copper is required for the synthesis of melanin a pigment which is present in the skin, hair, and eyes. Achromotrichia is a term used to describe lack of pigment in the hair and is a condition which has been observed in domestic and laboratory animals consuming diets low in copper (10).
Iron Deficient Anaemia– Copper has been shown to be required for the transportation of iron to the bone marrow for the purpose of red blood production (11). In severe copper deficiency, transport of iron to the bone marrow is disrupted allowing iron to accumulate in the tissues, potentially resulting in anaemia. A copper deficiency was found to be accompanied by a type of anaemia similar to that produced by iron deficiency (12), (13).
Arthritis- Copper contributes to maintenance of normal connective tissues. This means that it is important for the process involving the maintenance of the connective tissues present in joints. There is anecdotal evidence that copper is also involved in regulating inflammatory processes such as those linked with arthritic conditions. Many people choose to wear copper bracelets as they believe the copper may be absorbed directly through the skin.
Wound healing– Copper contributes to maintenance of normal connective tissues. This means that it is important for the process involving the maintenance of the connective tissues present in the skin. It stands to reason therefore that a deficiency in copper may lead to poor skin healing.
Anaemia- Copper contributes to normal iron transport in the body. This means that whilst anaemia is an ailment linked primarily with iron deficiency, insufficient quantities of copper may lead to the same symptoms as the iron is present but not being utilised effectively. Copper is required for conversion of iron to haemoglobin.
Although chronic copper toxicity is rare, even small amounts above the RDA can cause unwanted side effects such as nausea and vomiting. The Tolerable Upper Safe Level has been established at 10mg per day for adults in the UK. High intakes of copper adversely affects zinc absorption as both zinc and copper compete for absorption.