Copper in a diet is necessary for many different body functions, such as the production of normal red blood cells and the maintenance of healthy bones and nerves. Copper occurs naturally in a diet that includes an assortment of fruits, vegetables, beans, nuts and seafood. Deficiencies and toxicities are rare, but it is important to maintain a balance of this essential mineral with other nutrients in the diet by meeting and not greatly exceeding the dietary requirement for copper.
Function
Some of the many functions of copper in a diet include assisting in energy production, iron metabolism, connective tissue formation and brain and nervous system functions. Copper also functions as an antioxidant by neutralizing destructive substances in the body known as free radicals. At the same time, too much dietary copper can encourage the formation of free radicals, so a balance of copper in a diet is essential.
Deficiency
Because copper is found in many different types of foods, and very little is needed by the body, deficiencies are rare. When it occurs, a lack of copper in a diet can lead to a form of anemia, or a lack of iron-rich red blood cells, because iron is not properly metabolized without copper. White blood cell counts may also be affected by a lack of copper in a diet, resulting in compromised immunity and an increased susceptibility to infection. Rare but possible side effects of copper deficiency include loss of skin pigment, stunted growth, bone loss and neurological impairment.
Requirement
The amount of copper required in a diet is 900 micrograms for men and women ages 19 and above, according to the Institute of Medicine's Food and Nutrition Board. Although copper toxicity is rare, high amounts over time can lead to liver damage. As a result, the University of Florida Extension Service recommends getting no more than 10,000 mcg copper from diet and supplements combined.
Sources
The best sources of copper in a diet include shellfish such as oysters, clams, lobsters and crabs, nuts such as almonds, cashews, hazelnuts and peanuts, sunflower seeds, legumes such as beans and lentils and whole grain and fortified breakfast cereals. For instance, 3 oz. of cooked oysters contain 640 mcg of copper, 1 cup canned vegetarian baked beans contains 520 mcg and 1 oz. of peanuts contains 360 mcg. Significant amounts of copper are also found in mushrooms (390 mcg in 1/2 cup cooked), white and sweet potatoes (200 to 240 mcg in a medium baked), tofu (300 mcg in 1/2 cup firm), soy milk (350 mcg in 1 cup).
Considerations
Up to 45 percent more copper may be added to the diet from drinking water in some areas, mostly as a result of corroding plumbing, according to the Washington State Department of Health. Where there is old plumbing, the department recommends letting water from faucets run for at least 30 seconds, first thing in the morning before drinking, to eliminate excess copper that may have accumulated in pipes overnight.
