Age and copper intake do not affect copper absorption, measured with the use of 65Cu as a tracer, in young infants.

Abstract

BACKGROUND Copper homeostasis involves a high degree of regulation in which changes in absorption and biliary excretion are the main mechanisms. Whether neonates and small infants can make these changes efficiently is unknown. OBJECTIVE We evaluated the effect of age and copper intake on copper absorption in infants during the first 3 mo of life. DESIGN Thirty-nine healthy infants (19 infants aged 1 mo and 20 infants aged 3 mo) were selected. One-half of the subjects were randomly assigned to receive oral supplementation of 80 mg Cu (as copper sulfate). kg body wt(-1). d(-1) for 15 d. At the end of the trial, copper absorption was measured by using orally administered (65)Cu as a tracer and fecal monitoring of recovered (65)Cu. RESULTS Mean (+/- SD) copper absorption at 1 mo of age was 83.6 +/- 5.8% and 74.8 +/- 9.1% for the unsupplemented and supplemented infants, respectively. The corresponding figures at 3 mo of age were 77.6 +/- 15.2% and 77.7 +/- 11.3%. A two-way analysis of variance showed that age, copper supplementation, and the interaction between age and copper supplementation did not have a significant effect on copper absorption. There was an inverse correlation between total fecal copper and the percentage of (65)Cu absorption (r = -0.50, P < 0.003). CONCLUSION Copper absorption in young infants is high but does not respond to copper intake within the range tested.