Copper

What does it do?

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 antioxidantenzyme, 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.

Copper supplementation has been shown to increase SOD levels in humans.1

Where is it found?

The best source of copper is oysters. Nuts, dried legumes, cereals, potatoes, vegetables, and meat also contain copper.

Copper has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating Health Concerns
3Stars

Anemia
2Stars

High cholesterol

Menkes’ disease (injectable copper histidine)

Osteoporosis

Wound healing
1Star

Athletic performance

Benign prostatic hyperplasia

Cardiac arrhythmia

Hypoglycemia

Peripheral vascular disease

Rheumatoid arthritis

Sprains and strains
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

Who is likely to be deficient?

Many people consume slightly less than the “safe and adequate range” of copper, 1.5–3.0 mg per day. Little is known about the clinical effects of these marginally adequate intakes, though frank copper deficiency is uncommon. Children with Menkes’ disease are unable to absorb copper normally and become severely deficient unless medically treated early in life. Deficiency can also occur in people who supplement with zinc without also increasing copper intake. Zinc interferes with copper absorption.2 Health consequences of zinc-induced copper deficiency can be quite serious.3 In the absence of copper supplementation, vitamin C supplementation has also been reported to mildly impair copper metabolism.4 Copper deficiency can result in anemia, lower levels of HDL (“good”) cholesterol, or cardiac arrhythmias.

How much is usually taken?

Most people consume less than the recommended amount of this mineral. Some doctors recommend supplementing the average diet with 1–3 mg of copper per day. While the necessity of supplementing a normal diet with copper has not been proven, most people who take zinc supplements, including the zinc found in multivitamin-mineral supplements, should probably take additional copper.

Cupric oxide (CuO) is a form of copper frequently used in vitamin-mineral supplements sold over-the-counter. However, animal studies have shown conclusively this form of copper is poorly absorbed from the gut; it should therefore not be used in supplements.5 6 7 8 Several other forms of copper (including copper sulfate, cupric acetate, and alkaline copper carbonate) are better absorbed, and are therefore preferable to cupric oxide.9

Are there any side effects or interactions?

The level at which copper causes problems is unclear. But in combination with zinc, up to 3 mg per day is considered safe. People drinking tap water from new copper pipes should consult their doctor before supplementing, since they might be getting enough (or even too much) copper from their water. People with Wilson’s disease should never take copper.

Zinc interferes with copper absorption. People taking zinc supplements for more than a few weeks should also take copper (unless they have Wilson’s disease). In the absence of copper supplementation, vitamin C may interfere with copper metabolism. Copper improves absorption and utilization of iron.

Preliminary evidence shows that the levels of copper in the blood were higher among people who died from coronary heart disease than among those who did not.10 However, animals studies and some human studies suggest that, if anything, copper may prevent the development of heart disease. Although it is not clear why people who died of heart disease had elevated copper levels, this finding could be due to chronic inflammation, which is known to be associated with increased copper levels.11

Are there any drug interactions?
Certain medicines may interact with copper. Refer to drug interactions for a list of those medicines.

References

1. Jones AA, DiSilvestro RA, Coleman M, Wagner TL. Copper supplementation of adult men: effects on blood copper enzyme activities and indicators of cardiovascular disease risk. Metabolism 1997;46:1380-3.

2. Sandstead HH. Requirements and toxicity of essential trace elements, illustrated by zinc and copper. Am J Clin Nutr 1995;61(suppl):62S–4S.

3. Broun ER. Greist A, Tricot G, Hoffman R. Excessive zinc ingestion. A reversible cause of sideroblastic anemia and bone marrow depression. JAMA 1990;264:1441–3.

4. Jacob RA, Skala JH, Omaye ST, Turnlund JR. Effect of varying ascorbic acid intakes on copper absorption and ceruloplasmin levels of young men. J Nutr 1987;117:2109–15.

5. Aoyogi S, Baker DH. Bioavailability of copper in analytical-grade and feed-grade inorganic copper sources when fed to provide copper at levels below the chicks requirement. Poult Sci 1993;72:1075–83.

6. Baker DH, Odle J, Funk MA, Wieland TM. Bioavailability of copper in cupric oxide, cuprous oxide and in a copper-lysine complex. Poult Sci 1991;70:177–9.

7. Cromwell GL, Stahly TS, Moneque HJ. Effects of source and level of copper on performance and liver copper stores in weanling pigs. J Anim Sci 1989;67:2996–3002.

8. Ledoux DR, Henry PR, Ammerman CB, et al. Estimation of the relative bioavailability of inorganic copper sources for chicks using tissue uptake of copper. J Anim Sci 1991;69:215–22.

9. Baker DH. Cupric oxide should not be used as a copper supplement for either animals or humans. J Nutr 1999;129:2278–9.

10. Ford ES. Serum copper concentration and coronary heart disease among US adults. Am J Epidemiol 2000;151:1182–8.

11. Youssef A, Wood B, Baron DN. Serum copper: a marker of disease activity in rheumatoid arthritis. J Clin Pathol 1983;36:14–17.