Copper supplementation: failure to increase plasma copper and ceruloplasmin concentrations in healthy infants.

Plasma copper and ceruloplasmin concentrations at ages 0, 2, 4, 6, 9, and 12 mo were longitudinally evaluated in our Finnish nutritional survey of 200 infants. The infants, who were weaned by age 3.5 mo, were randomly assigned to receive either a liquid cow-milk-based formula containing 1.3 mumol Cu/L (n = 16) or the same formula supplemented with 7.8 mumol Cu/L as Cu sulfate (n = 16). They were compared with exclusively breast-fed infants. Plasma Cu and ceruloplasmin concentrations increased steadily and similarly in all three groups from 4.6 +/- 0.2 mumol/L (means +/- SEM) and 0.9 +/- 0.1 mumol/L, respectively, in umbilical samples to 19.7 +/- 0.3 mumol/L and 3.2 +/- 0.1 mumol/L, respectively, at age 12 mo. Our results indicate that concentrations of plasma Cu and ceruloplasmin in healthy full-term infants are resistant to dietary supplementation.