Fundamentals of Human Nutrition/Copper
Copper is one of nine trace minerals, which are mainly utilized as part of enzymes and hormones that are required for metabolism. This section will cover the sources of copper; the functions of copper within the body; the dietary requirements for copper; and copper imbalances in the body.
Copper can be found in many different foods, both animal and plant based. The richest sources of copper include oysters, whole grains, legumes, potatoes, and nuts. Other sources of copper in food include black pepper, yeast, prunes, cocoa, and dark leafy vegetables (U.S. National Library of Medicine, 2015).
The main function of copper is as a catalyst for different biochemical reactions in the body. Possibly it’s most important role is in hemoglobin synthesis. Copper is cofactor in several enzymes that speed up the oxidation of iron. It is this iron that forms red blood cells, which are necessary for transport of oxygen throughout the body (U.S. National Library of Medicine, 2015; Texas Heart Institute, 2015). Other important role of copper include the production of collagen, elastin, melanin, and neurotransmitters (Texas Heart Institute, 2015) as well as natural defenses against damage caused by free radicals (Whitney & Rolfes, 2013).
The EAR (Estimated Average Requirement) of copper for children, ages 1 to 18 years, varies between 260 μg/day to 685 μg/day, increasing with age. The RDA (Recommended Dietary Allowance) is slightly higher, ranging from 340 μg/day to 890 μg/day. The EAR for adults, ages 19 and older, is 700 μg/day. The RDA is 900 μg/day. These numbers are set, regardless of gender. In pregnancy, women need a slightly higher copper intake, as a baby delivered at full term contains 13.7 mg of copper, which must be taken from the mother during pregnancy. Lactating mothers also require a higher copper intake. For both pregnant and lactating women, the EAR is 1,000 μg/day and the RDA is 1,300 μg/day (Institute of Medicine (US) Panel on Micronutrients, 2001).
Imbalance of copper can be seen in two different genetic diseases. First, Menkes syndrome is the name given to a copper deficiency. This deficiency is marked by bone abnormalities, seizures, weakness in limbs, and brittle, kinky hair (Dutchen, 2012). It results from intestinal cells absorbing copper but not being able to release it back into circulation. This very rare disease occurs before birth, as it is an inherited disorder. Although it can be carried by females, only males can develop the disease. While some treatment options exist, such as copper injections into the bloodstream or under the skin, prognosis is not good, with most males dying within the first few years of life. The second genetic disease involving copper is Wilson’s disease. Also known as Hepatolenticular degeneration, it is an autosomal disorder in which copper transport is hindered. This hindrance results in a buildup of copper that is deposited in the brain, kidney, liver, and eyes. These deposits can cause liver damage, scarring, kidney failure, and death in some cases (Dutchen, 2012; U.S. National Library of Medicine, 2014). Some of the symptoms of Wilson’s disease include dementia, ataxia, abdominal distention, impaired speech, tremors, and jaundiced eyes or skin. In order to test for Wilson’s, patients may be given a slit-lamp eye examination to show eye movement as well as rust-colored rings around the iris. These rings are a result of the copper deposits in the eye. Other tests may include a urine copper test, abdominal MRI, or liver biopsy. The goal of treatments is to reduce the copper in the body’s tissues. There are many medications that may be used, but regardless of medication, the treatment must be lifelong (U.S. National Library of Medicine, 2014).
Copper in diet: MedlinePlus Medical Encyclopedia. (2015). Retrieved November 11, 2015, from https://www.nlm.nih.gov/medlineplus/ency/article/002419.htm Dutchen, S. (2012). Inside Life Science. Retrieved November 11, 2015, from http://publications.nigms.nih.gov/insidelifescience/metals-sickness-health.html Institute of Medicine (US) Panel on Micronutrients. (2001). Retrieved November 11, 2015, from http://www.ncbi.nlm.nih.gov/books/NBK222312/ Trace Elements: What They Do and Where to Get Them - Texas Heart Institute Heart Information Center. (2015). Retrieved November 11, 2015, from http://www.texasheart.org/HIC/Topics/HSmart/trace1.cfm Whitney, E. and Sharon Rady Rolfes. (2013). Understanding Nutrition. Stamford, CT: Cengage Learning. Wilson disease: MedlinePlus Medical Encyclopedia. (2014). Retrieved November 11, 2015, from https://www.nlm.nih.gov/medlineplus/ency/article/000785.htm