Nutritional Deficiencies - Health Concerns

Copper - updated: 01 December 2008

Essentiality of copper in humans

Am J Clin Nutr. 1998 May;67(5 Suppl):952S-959S

Uauy R, Olivares M, Gonzalez M.

The biochemical basis for the essentiality of copper, the adequacy of the dietary copper supply, factors that condition deficiency, and the special conditions of copper nutriture in early infancy are reviewed. New biochemical and crystallographic evidence define copper as being necessary for structural and catalytic properties of cuproenzymes. Mechanisms responsible for the control of cuproprotein gene expression are not known in mammals; however, studies using yeast as a eukaryote model support the existence of a copper-dependent gene regulatory element. Diets in Western countries provide copper below or in the low range of the estimated safe and adequate daily dietary intake. Copper deficiency is usually the consequence of decreased copper stores at birth, inadequate dietary copper intake, poor absorption, elevated requirements induced by rapid growth, or increased copper losses. The most frequent clinical manifestations of copper deficiency are anemia, neutropenia, and bone abnormalities. Recommendations for dietary copper intake and total copper exposure, including that from potable water, should consider that copper is an essential nutrient with potential toxicity if the load exceeds tolerance. A range of safe intakes should be defined for the general population, including a lower safe intake and an upper safe intake, to prevent deficiency as well as toxicity for most of the population.

Publication Types:

• Review

Copper deficiency in humans

Semin Hematol. 1983 Apr;20(2):118-28

Williams DM.

Copper is an essential trace element that is required for a number of enzymes which are necessary for normal metabolic function. Metabolic balance studies have demonstrated that daily copper losses are approximately 1.3 mg/day. In order to remain in copper balance, the average adult male must consume a diet which contains at least 2 mg copper/day. It has been assumed that most diets satisfy this requirement because of the ubiquitous presence of copper in most foodstuffs. Recent studies, however, have shown that dietary copper may often fall below the estimated daily needs. Nevertheless, clinically evident copper deficiency has been documented in only a few situations. Of these disorders. Menkes' syndrome has been most intensively studied. This x-linked abnormality is associated with copper deficiency due to impaired gastrointestinal copper absorption. However, the clinical disorder cannot be corrected readily with copper replacement, thus suggesting that Menkes' syndrome may reflect more than simple copper deficiency. Nutritional copper deficiency appears to be well documented in two situations: (1) the newborn, usually premature, undergoing rapid growth on a diet poor in copper, and (2) the patient maintained on total parenteral nutrition for long periods of time without copper supplementation. In both of these situations, anemia and neutropenia are the most striking hematologic abnormalities associated with copper deficiency. Sideroblastic changes as well as nuclear maturation defects observed in erythroid precursors. However, suggest that there is an effect of copper deficiency on the hematopoietic system which cannot be explained solely by defective plasma iron transport.

Publication Types:

• Review

The role of copper, molybdenum, selenium, and zinc in nutrition and health

Clin Lab Med. 1998 Dec;18(4):673-85

Chan S, Gerson B, Subramaniam S.

Copper, zinc, selenium, and molybdenum are involved in many biochemical processes supporting life. The most important of these processes are cellular respiration, cellular utilization of oxygen, DNA and RNA reproduction, maintenance of cell membrane integrity, and sequestration of free radicals. Copper, zinc, and selenium are involved in destruction of free radicals through cascading enzyme systems. Superoxide radicals are reduced to hydrogen peroxide by superoxide dismutases in the presence of copper and zinc cofactors. Hydrogen peroxide is then reduced to water by the selenium-glutathione peroxidase couple. Efficient removal of these superoxide free radicals maintains the integrity of membranes, reduces the risk of cancer, and slows the aging process. On the other hand, excess intake of these trace elements leads to disease and toxicity; therefore, a fine balance is essential for health. Trace element--deficient patients usually present with common symptoms such as malaise, loss of appetite, anemia, infection, skin lesions, and low-grade neuropathy, thus complicating the diagnosis. Symptoms for intoxication by trace elements are general, for example, flu-like and CNS symptoms, fever, coughing, nausea, vomiting, diarrhea, anemia, and neuropathy. A combination of observation, medical and dietary history, and analyses for multiple trace elements is needed to pinpoint the trace element(s) involved. Serum, plasma, and erythrocytes may be used for the evaluation of copper and zinc status, whereas only serum or plasma is recommended for selenium. Whole blood is preferred for molybdenum. When trace element levels are inconsistent with medical evaluations, a test for activity of the suspected enzyme(s) would support the differential diagnosis. Furthermore, it is important to differentiate whether trace element deficiency or toxicity is the primary cause of the disorder, or is secondary to other underlying diseases. Only successful treatment of the primary disorder will lead to complete recovery. In the event of sample contamination during collection or analysis, the physician may be misled by falsely elevated results. Royal blue top evacuated tubes containing negligibly low concentrations of the trace element or acid-washed plastic sterilized syringes should be used for blood, serum, or plasma collection. Powdered gloves must be avoided. When possible, mineral supplements are not to be administered to the patient for a minimum of 3 days prior to sample collection. Serum and plasma specimens are to be transported in acid-washed polypropylene and polyethylene tubes. Analysis is performed in a controlled environment to minimize or eliminate contamination. During analysis, all laboratory wares should be acid-washed for decontamination. A detailed description of these precautions may be found in reviews by Aitio and Jarvisalo and by Chan and Gerson. Copper and zinc analysis on serum and plasma are commonly performed by flame atomic absorption spectrometry, inductively coupled plasma-atomic emission spectrometry, and inductively coupled plasma-mass spectrometry. Serum and plasma selenium levels are determined by graphite furnace atomic absorption with Zeeman background correction and neutron activation analysis. Molybdenum levels are best determined by neutron activation and highly sensitive inductively coupled plasma-mass spectrometry

Publication Types:

• Review

Publication Types:

• Review

Publication Types:

• Review