Vitamin C in premature and full term human neonates

Plasma concentrations of vitamin C (ascorbic acid, AA) are known to be higher in full-term human neonates than their mothers. Immaturity of placental AA transport could result in low plasma AA concentrations in pre-term infants, We found that plasma AA concentrations in umbilical cord blood of 25 full-term neonates (38-42 weeks gestation) and 33 pre-term neonates (24-36 weeks gestation) were always significantly higher than in the corresponding maternal blood (P <0.0001). However, plasma AA levels were significantly higher in pre-term than in full-term infants (146+/-93 vs 102+/-27 mu M, respectively; P=0.03). Furthermore, a rapid and sharp decrease in plasma AA concentrations from 229+/-166 mu M to 45+/-18 mu M (P <0.0001) over the first 3 days of life was observed in eight very low birth weight infants (460-1090 g, 24-28 weeks gestation). These findings raise important questions about the in utero functions of AA in the developing fetus and the adequacy of postnatal vitamin C supplementation of the premature infant.