Copper is found in many foods in small amounts (oysters and nuts are the richest sources). The standard amount available in our diet, whether or not it is excessive or deficient, is a controversial topic; the naturalist in me feels that if it is in wholesome foods, it must be the right amount. This mineral is present in water that flows through copper piping. Increases in estrogen hormone levels, from taking birth control pills or during pregnancy, for example, often increase serum copper levels to more than double normal values, while red blood cell levels, where copper is important, may actually be lower. This may contribute to some of the psychological or other symptoms seen during pregnancy or with birth control pill use. Increased copper levels have been associated with schizophrenia, learning disabilities, and senility, although none of these associations have been demonstrated with certainty. Depression and other mental problems, premenstrual syndrome, and hyperactivity have also been correlated with high copper levels, often in combination with low zinc levels.

Zinc and copper have a seesaw relationship in the body, competing with each other for absorption in the gut. Both zinc deficiency and copper toxicity have increased since the switch from zinc (galvanized) to copper water pipes. We can avoid this problem by not drinking tap water. Some studies of schizophrenics have revealed high blood copper with low urinary copper (showing that copper is being retained) and low blood zinc. In some of these cases, zinc was helpful as an antianxiety agent.

About 30 percent of copper intake is absorbed into the body from the stomach and upper intestine; it is fairly rapidly absorbed, usually within 15 minutes. Copper is transferred by albumin across the gut wall and carried to the liver, where it is formed into ceruloplasmin, a copper-protein complex. About 90 percent of the average 100 mcg. of copper in the blood is in the form of ceruloplasmin. As a balancing mechanism to minimize copper toxicities, absorption of copper is decreased when ceruloplasmin levels are adequate. Vitamin C, zinc, and manganese all interfere with copper absorption. Protein and fresh vegetable foods have been shown to improve copper absorption.

About 100 mg. of copper are stored in the body, with the highest concentrations in the liver and brain tissues, which account for about one-third of the total. Muscles contain approximately another third, with the remaining copper in the other tissues. At birth, a high amount is contained in the liver; by about age ten, the normal adult level of copper is reached, both in the liver and the rest of the body. Excess copper is eliminated mainly through the liver into the bile and is lost through the intestines. A minimal amount is excreted in the urine.

Sources: Copper is available in most natural foods. Some authorities believe that our average intake is higher than our actual needs, that low intakes are uncommon, and that toxicity is a potential problem. The other school of thought holds that low intake is common because soil depletion has decreased the copper level in many foods and because many people avoid natural, copper-containing foods.