Copper

Overview

Copper is an essential trace mineral that is a cofactor in cuproenzyme systems. After being absorbed, it is carried on transcuprein and albumin to the liver where it is incorporated into liver enzymes. These are secreted into the blood as ceruloplasmin, which is a copper-carrying protein that is an important blood-based antioxidant.

Dosage Info

Dosage Range

Dosages that have been used in clinical studies range from 0.2-7.5mg daily. (1)

Most Common Dosage

2mg daily.

Dosage Forms

Tablets, capsules, and liquids.

Adult RDI

2mg

Adult ODA

2-3mg

RDA

  • Infants < 6 months: 200mcg (Adequate Intake, AI)
  • Infants 7-12 months: 220mcg (AI)
  • Children 1-3 years: 340mcg
  • Children 4-8 years: 440mcg
  • Children 9-13 years: 700mcg
  • Children 14-18 years: 890mcg
  • Adults >19 years: 900mcg
  • Pregnancy: 1,000mcg
  • Lactation : 1,300mcg

Interactions and Depletions

Interactions

Depletions

Active Forms

copper gluconate, amino acid chelates, glycinate, lysinate, citrate, sulfate, and sebacate.

Absorption

Soluble copper can be absorbed from the stomach and upper duodenum in humans. Copper in foods is in bound form and must undergo digestion before it can be released and absorbed from the duodenum.

Toxicities & Precautions

General

Copper toxicity is rare.

Side Effects

Tissue elevations only occur when intakes are 200 to 500 times above normal. Symptoms include GI disturbances, salivation, a metallic taste in the mouth, headache, dizziness, and weakness. Severe toxicity causes hypertension, liver damage, (2) , (3) kidney failure, and death.

In cases of elevated copper, the problems that develop may not be due to copper toxicity, but rather its interference with the absorption and distribution of other metal ions such as iron and zinc. Wilson’s disease is a genetic disorder that causes a toxic accumulation of copper in the liver, kidney, cornea of the eye, and central nervous system. Treatment involves a low copper diet and use of penicillamine which facilitates copper excretion. Occasional copper toxicity has been reported in individuals who live in houses with copper water pipes where copper leaches into the drinking water.

Functions in the Body

Oxygen Transport:

Required for the synthesis and function of hemoglobin, and, therefore, it plays a central role in the transport of oxygen throughout the body.

Iron:

Stimulates the absorption of iron.

Collagen Synthesis:

Is copper dependent and determines the integrity of bone, cartilage, skin, and tendons.

Structural Elasticity:

Involved in the production of elastin and collagen, which are the proteins that provide the structural elasticity to tissues in the lungs, blood vessels, and skin.

Component of Enzymes:

a) copper-zinc superoxide dismutase (SOD) which is one of the body’s most important antioxidant enzymes.
b) dopamine beta-hydroxylase, which oxidizes ascorbic acid and synthesizes norepinephrine.

Clinical Applications

Osteoporosis

Mild copper deficiency is implicated in the onset and progression of osteoporosis. (4) , (5)

Cyctic fibrosis

Those with cystic fibrosis may be moderately copper deficient. (6)

Rheumatoid Arthritis

Copper salicylate has significant anti-inflammatory activity. (7)

Symptoms and Causes of Deficiency

Severe copper deficiency is rare, but marginal copper deficiency is common since the diet of many Americans only supplies about 50 percent of the RDA. The symptoms of copper deficiency include: loss of color in the hair and skin (due to decreased synthesis of melanin), anemia, fatigue, kinky hair, low body temperature, breakdown of connective tissue, various cardiovascular problems, nervous system disorders, and reduced resistance to infection.

    Zinc interferes with copper absorption. High intake of zinc supplements can lead to copper deficiency. Menkes’ disease, also called kinky or steely hair syndrome, is a genetic defect in copper absorption characterized by stunted growth, abnormalities in cardiovascular and skeletal development, progressive cognitive decline, and premature death. Some researchers have shown that copper deficiency is associated with elevated cholesterol and triglycerides, and the development of atherosclerosis. Thus, copper deficiency may play a role in the risk of cardiovascular disease.

Dietary Sources

Copper-containing foods include oysters, organ meats, whole grain breads and cereals, shellfish, dark green leafy vegetables, dried legumes, nuts, and chocolate.

References

  1. View Abstract: Turnlund JR, Keyes WR, Peiffer GL, Scott KC. Copper absorption, excretion, and retention by young men consuming low dietary copper determined by using the stable isotope 65Cu. Am J Clin Nutr. Jun1998;67(6):1219-1225.
  2. View Abstract: Aburto EM, Cribb A, Fuentealba IC. The failure of selenium supplementation to prevent copper-induced liver damage in Fischer 344 rats. Can J Vet Res. Apr2001;65(2):104-10.
  3. View Abstract: O'Donohue J, Reid M, Varghese A. A case of adult chronic copper self-intoxication resulting in cirrhosis. Eur J Med Res. Jun1999;28;4(6):252.
  4. View Abstract: Strain JJ. A Reassessment of Diet and Osteoporosis—Possible Role for Copper. Med Hypotheses. Dec1988;27(4):333-38.
  5. View Abstract: Klevay LM. Lack of a recommended dietary allowance for copper may be hazardous to your health. J Am Coll Nutr. Aug1998;17(4):322-6.
  6. View Abstract: Best K. Copper enzyme activities in cystic fibrosis before and after copper supplementation plus or minus zinc. Metabolism. 2004 Jan;53(1):37-41.
  7. View Abstract: Sorenson JR, et al. Treatment of Rheumatoid and Degenerative Diseases with Copper Complexes: A Review with Emphasis on Copper-salicylate. Inflammation. Sept1997;2(3):217-38.