Trace element concentrations in patients on home enteral feeding: two cases of severe copper deficiency

Abstract

Enteral feeding is the fastest growing area of artificial nutrition, with the annual rate of growth being estimated at 20-25% a year. Previous studies have demonstrated trace element deficiencies in patients on long-term home enteral nutrition (HEN). The trace elements zinc, selenium, copper and manganese were measured in blood samples from 37 patients on HEN using atomic absorption spectroscopy. Plasma zinc concentrations (range 7.4-14.4 micromol/L) were below the reference range (12.6-22.0 micromol/L) in 30 patients, plasma selenium concentrations (range 0.73-1.76 micromol/L) were below the reference range (0.8-2.0 micromol/L) in only one patient. Whole blood manganese (range 74-309 nmol/L) and plasma manganese (range 13-51 nmol/L) were above both respective reference ranges (73-210 nmol/L and 9-24 nmol/L) in four patients. Two patients showed severely low plasma copper concentrations of 2.4 micromol/L and 2.5 micromol/L, and responded to treatment with extra copper supplementation. Although enteral feeds contain adequate concentrations of trace elements, problems with bioavailability may occur and patients receiving long-term enteral feeding should be monitored with regard to plasma trace element concentrations.