Biochemical, metabolic, and clinical role of copper in human nutrition

Trace mineral balance during acute diarrhea in infants

To evaluate the magnitude of copper and zinc losses during acute diarrhea requiring hospitalization, we studied 14 infants, 3 to 14 months of age, and compared them with a control group of 15 infants of similar age, birth weight, and nutritional status. Metabolic balance studies were conducted in the study group during an initial 48 hours (period 1) and on days 6 and 7 after admission (period 2). The control group was studied after recovery from respiratory disease. Copper and zinc content of feces, urine, and food samples was measured by atomic absorption spectrophotometry. Mean (+/- SD) fecal losses were higher for period 1 in the diarrhea group than in control subjects: Cu 55.7 +/- 21.2 versus 28.8 +/- 6.7 micrograms/kg/body weight/day (p less than 0.01); Zn 159.4 +/- 59.9 versus 47.4 +/- 6.4 micrograms/kg/day (p less than 0.0001). For period 2, Zn losses were similar in both groups, but Cu balance remained negative only in the study group. Retention of Zn for the study group went from -21.2 +/- 46.7 in period 1 to 204.5 +/- 103.0 micrograms/kg/day in period 2 (p less than 0.0001), and fecal weight decreased from 70.5 +/- 20.6 in period 1 to 36.8 +/- 20.0 gm/kg/day in period 2. Fecal weight and fecal losses were correlated: r = 0.71 (p less than 0.01) for Cu and r = 0.81 (p less than 0.001) for Zn. Plasma mean Cu and Zn levels were low in period 1 but rose in period 2, especially for Zn. A negative correlation was found between fecal Zn losses and plasma Zn: r = 0.74 (p less than 0.001). We conclude that acute diarrhea leads to Cu and Zn depletion and that plasma levels and Cu balance remain abnormal a week after admission.

Energy, protein, zinc and copper status of twenty-one elderly inpatients: analysed dietary intake and biochemical indices

1. Duplicate diet analysis for energy, protein, zinc and copper with estimates of biochemical status for Zn and Cu were undertaken in twenty-one elderly long-stay inpatients (mean age 82 (range 63-89) years) consuming their customary hospital diet and in a stable medical condition. Fourteen patients had a long-standing and significant healing problem, either a leg ulcer or pressure sore. 2. Mean daily intakes of energy (5.2 MJ), protein (45 g), Zn (85 mumol) and Cu (14 mumol) were low in comparison with both official recommendations and levels of intake at which metabolic equilibrium was observed in healthy elderly people studied by the same methods (Bunker et al. 1984a). 3. Mean leucocyte Zn (9 pmol/10(6) cells) and Cu (7.5 pmol/10(6) cells) were low in comparison with results from healthy elderly people (Bunker et al. 1984a), implying suboptimal status for these elements. Those patients with healing problems tended to have the lower values within the range. 4. Recommendations are made with respect to improving nutritional status in this disadvantaged group of people.

Neutropenia due to copper deficiency in total parenteral nutrition

Copper (Cu) deficiency has been reported both in pediatric and adult patients on total parenteral nutrition (TPN). Manifestations of Cu deficiency are usually hematologic in the adult. A 56-yr-old patient with a history of subtotal gastrectomy underwent massive small bowel resection and partial colectomy in 1977. TPN was initiated. Intravenous (iv) trace mineral supplements were not available in 1977 at our institution. By June 1978, the patient manifested neutropenia with a white blood cell (WBC) count of 2000/mm3 and 39% neutrophils or a total neutrophil count (TNC) of 780/mm3. The serum Cu level at that time was 5 micrograms/dl (normal, 70-140), and the serum zinc (Zn) level was low, although within normal limits. Oral supplementation with Cu and Zn tablets proved ineffective. Twice weekly infusions of fresh frozen plasma were begun in April 1979, and intravenous chromium supplementation started in September 1979, but neither the WBC count nor the TNC improved. Intravenous Cu and Zn were approved in October 1979, and were added to the TPN formula. Within 2 weeks, the WBC count rose to 6300/mm3, and the neutrophils increased to 83% with a TNC of 5229. After 12 weeks, the serum Cu level rose to 80 micrograms/dl. The increase in WBC count and percentage of neutrophils can be attributed to the addition of Cu to the TPN infusate.