Even a mild copper deficiency impairs the ability of white blood cells to fight infection. Copper is necessary for proper absorption of iron in the body, and it is found primarily in foods containing iron. If the body does not get a sufficient amount of copper, hemoglobin production decreases and copper-deficiency anemia can result.

One of the first signs of copper deficiency is osteoporosis. Copper is essential in the formation of collagen, one of the fundamental proteins making up bones, skin and connective tissue. Other possible signs of copper deficiency include anemia, baldness, diarrhea, general weakness, impaired respiratory function, and skin sores. A lack of copper can also lead to increased blood fat levels. 

Various enzyme reactions require copper as well. Copper is needed as a cross-linking agent for elastin and collagen, as a catalyst for protein reactions, and for oxygen transport. It is also used for the metabolism of essential fatty acids. Copper deficiency can produce various symptoms, including diarrhea, inefficient utilization of iron and protein, and stunted growth. In babies, the development of structure of these body parts may be altered.

Since copper is not manufactured by the body, it must be taken in through the diet or supplementation. For the body to work properly, it must have a proper balance of copper and zinc; and imbalance can lead to thyroid problems. In addition, low (or high) copper levels may contribute to mental and emotional problems. Copper deficiency may be a factor in anorexia nervosa, for example.

A Recommended Daily Allowance for copper has not been determined, but the National Research Council recommends that adults get from 1.5 to 3.0 mg per day, 1.5 to 2.5 milligrams for children, and 0.4 to 0.6 milligrams for infants less than six months old. Even a normal ‘healthy’ diet will not usually provide the correct amount of copper for most people because of the mineral deficiency of most food producing soils.

Copper deficiency is especially likely to occur in babies who are fed only cow’s milk, persons suffering from sprue or kidney disease, and those who chronically take megadoses of zinc. Long–term use of oral contraceptives can also upset the balance of copper in the body, causing either excessively high or excessively low copper levels.

Note: Although copper intake is required for health and deficiency is more likely than not, an excessive intake of copper can lead to toxicity and may have symptoms of depression, irritability, nausea and vomiting, nervousness, and joint and muscle pain. Ingesting 10 milligrams or more at a time may cause nausea and sixty milligrams generally results in vomiting. Children can be affected at much smaller dosage levels.