The trace minerals are an interesting necessity in the body. Generally when we think of copper, it's in terms of pans or pipes or wire. But copper is a vitally essential nutrient in the body. Our bodies can't make copper - it must come from the diet. Swallowing pennies won't help!
Copper was first found as a normal part of blood serum in 1875. It is found not only in the blood, but also the brain, liver, muscle, kidneys, bones, teeth and heart. Not much copper is actually stored in the body, but it is estimated we have between 50mg and 120 mg in us at any given time. By way of comparison, a current U. S. penny weighs about 2.5 grams - at least 20 times the amount roaming around our body!
Functions in the Body. Copper is critical partly because it is an enzyme co-factor in a number of biochemical processes. It also works as an intermediary in electron transfers in other reactions. It's hard to imagine sometimes, but remember back to your school days in science class. When doing any experiment, if your ingredients/raw materials weren't exactly as indicated, you wouldn't get the same/desired result. You can make a chocolate cake without an egg, but it won't be the same chocolate cake, right? So while there may be only one copper atom in a particular reaction, if it's not there, the end result either cannot happen or will be altered in some way.
Copper has an intimate relationship with iron, making the iron more absorbable and more available from the liver. It acts as an anti-oxidant with superoxide dismutase. It assists in the generation of ATP, our cellular energy form. Copper assists in the synthesis of catecholamines in the brain and adrenal glands, myelin of nerves, healthy connective tissue and blood vessels. It is involved somehow in the management of cholesterol, however unclear. There is also some evidence of copper having anti-cancer properties. Copper is something we want around!
Interactions with Others. Copper mixes it up with a lot of other things in the body in positive and negative ways. One significant relationship is with zinc. Zinc intake, even in fairly low doses, can interfere with copper absorption. Because of this, many zinc supplements have a bit of copper added to them. On the other hand, too much copper can also inhibit zinc's availability. On a practical level, however, we don't take copper supplements and this is rarely an issue. In much higher doses, iron, molybedenum, calcium, phosphorus and Vitamin C may all reduce copper levels. Fiber can bind to copper and increase its elimination. Fructose appears to exacerbate copper deficiency, as do the heavy metals cadmium, mercury and silver. We have less exposure to the metals, but fructose, especially in high fructose corn syrup, is all too present in the diet. Some medications may also contribute to copper loss and/or deficiency, including some NSAIDS and corticosteroids.
Deficiency and Symptoms. Increasingly, low copper states are not uncommon. As it is essential for moving iron, copper deficiency may result in an anemia. Other problems may include low white blood cells, degeneration of blood vessels, loss of pigment in skin and/or hair, impaired immune function, liver and brain damage. Besides the possible interference by other minerals, deficiency may also be caused by damage to the small intestine so that it cannot absorb the copper, even if it's there waiting, as in Celiac disease or other inflammatory bowel conditions. There is also an (uncommon) chromosomal disorder, Menkes Syndrome, that results in low copper status.
Toxicity and Symptoms. Toxicity is rare in the United States, but acute poisoning can occur with excess intake. Mild symptoms may be nausea, vomiting and diarrhea. In extreme cases, symptoms may include jaundice or blood in the urine or little or no urine production at all. Copper can be lethal in very high doses. Wilson's Disease causes an accumulation of copper and damage in the liver, brain and eyes.
Recommendations & Sources. The established Recommended Daily Allowance of copper in the diet for adults is about 900 micrograms (mcg) a day, so just under 1 milligram (mg). It has been estimated that the average American gets between 1.2-1.7 mg in their diets, but that only half of that amount is actually absorbed for use. With these calculations, it is clearly borderline as to whether we get enough copper daily. There are many delicious sources of copper available to us. Sesame, pumpkin and sunflower seeds, lentils, garbanzo, lima and pinto beans, mushrooms, cashews and walnuts, asparagus, kale, mustard greens are just a start. You can see a bigger list here - World's Healthiest Foods.
As always, getting the nutrients we need are always best coming from a healthy, well-rounded diet. But if you are taking a lot of zinc or have other complicating factors, check your supplements for copper and talk to your health care provider about how to be sure your copper levels are optimal.
Resources: Advanced Nutrition & Human Metabolism, James L. Groff & Sareen S. Gropper, Nutritional Biochemistry & Metabolism, Maria C. Linder, Medical Nutrition, Russell B. Marz, www.whfoods.com, www.drweil.com