To evaluate the vitamin C nutritional status of premature infants, plasma vitamin C concentrations were measured in 7 neonates born before 32 wk of gestation and in 13 premature infants born at or after 32 wk of gestation. Samples of umbilical venous plasma from 14 full-term infants were analyzed to provide reference values. Oral feedings with pooled, pasteurized milk from human donors were initiated 1-3 days after birth and intake was gradually increased to 200 ml X kg X day during the second week. After 2 wk, the 13 larger infants received approximately half of their daily milk intake from their own mothers. Results showed that plasma concentrations of vitamin C decline rapidly after birth and approach very low levels in preterm infants fed pasteurized, pooled human milk.