From the Guidelines
Copper is a vital trace element that plays a crucial role in various biological functions, including energy production, iron metabolism, and connective tissue formation, and its recommended daily intake for adults is approximately 900 micrograms. The essentiality of copper in mammals was established in 1928 1, and it serves as an essential catalytic cofactor in redox chemistry for proteins involved in growth and development. Copper enzymes regulate energy production, iron metabolism, connective tissue maturation, and neurotransmission, and it is essential for cholesterol, thyroid hormone, and glucose metabolism, aspects of immune function, blood pressure control, and the formation of melanin pigment 1.
Biological Functions of Copper
- Energy production: Copper is necessary for the production of ATP, the energy currency of the cell.
- Iron metabolism: Copper plays a role in the absorption and transport of iron, which is essential for the formation of hemoglobin and red blood cells.
- Connective tissue formation: Copper is crucial for the production of collagen and elastin, which maintain skin, blood vessel, and bone health.
- Immune function: Copper contributes to the functioning of the immune system, particularly in the activation of immune cells.
- Antioxidant defense: Copper-containing enzymes like superoxide dismutase help protect cells from oxidative damage.
Copper Homeostasis
The body maintains copper homeostasis primarily through regulation in the liver and intestines 1, 2. The liver utilizes some copper for metabolic needs, synthesizes and secretes the copper-containing protein ceruloplasmin, and excretes excess copper into bile. Processes that impair biliary copper excretion can lead to increases in hepatic copper content, which can cause liver damage and other health problems.
Dietary Sources and Recommended Intake
Copper is naturally found in foods such as shellfish, nuts, seeds, whole grains, and chocolate 3. The recommended daily intake for adults is approximately 900 micrograms, with a dietary reference intake (DRI) ranging from 1.1 to 2 mg/day 3. However, copper absorption is highly variable, ranging from 20 to 50% 3, and excessive copper can cause toxicity symptoms, including liver damage. A no-observed-adverse-effect level (NOAEL) of 10 mg/day was identified in a 12-week, double-blind study in seven adults testing up to 12 mg/day 3.
From the FDA Drug Label
Copper is an essential nutrient which serves as a cofactor for serum ceruloplasmin, an oxidase necessary for proper formation of the iron carrier protein, transferrin. Copper also helps maintain normal rates of red and white blood cell formation The biological uses of copper include:
- Serving as a cofactor for serum ceruloplasmin
- Helping maintain normal rates of red and white blood cell formation
- Necessary for proper formation of the iron carrier protein, transferrin 4
From the Research
Biological Uses of Copper
The essential trace mineral copper plays a crucial role in various biological processes, including:
- Hemoglobin synthesis 5
- Neurotransmitter function 5
- Iron oxidation 5
- Cellular respiration 5
- Antioxidant defense peptide amidation 5
- Formation of pigments and connective tissue 5
- Host response to bacterial infection 6
- Regulation of immunity 6
- Lipid homeostasis 6
- Red and white cell maturation 7
- Iron transport 7
- Cholesterol and glucose metabolism 7
- Myocardial contractility 7
- Brain development 7
- Stabilization of the extracellular matrix 8
- Elimination of free radicals 8
- Synthesis of hormones and neurotransmitters 8
Copper Deficiency
Copper deficiency can result in various clinical manifestations, including:
- Anemia 5, 7, 9
- Neutropenia 7
- Bone abnormalities 7
- Hypopigmentation of the hair 7
- Hypotonia 7
- Impaired growth 7
- Increased incidence of infections 7
- Alterations of phagocytic capacity of the neutrophils 7
- Abnormalities of cholesterol and glucose metabolism 7
- Cardiovascular alterations 7
- Myeloneuropathy 9
- Cutaneous and immune system effects 9
Copper Homeostasis
Copper homeostasis is essential for maintaining proper physiological functions, and disruption of copper homeostasis may underlie the development of various diseases, including: