Nonglucose carbohydrates such as galactose, mannose, and inositol play a clinically important role in fetal and neonatal nutrition, though little is known about their metabolism in the neonate. The aim of this study was to determine whether postprandial changes in plasma carbohydrate and sugar alcohol concentrations are affected by clinical variables such as postnatal age (PNA), milk type, feeding volume, or feeding duration in term newborns. Neonates (n ϭ 26) taking intermittent enteral feedings were enrolled. Blood samples were obtained at baseline (immediately before the start of a feeding) and at 2-3 subsequent time points up to 110 min. Postprandial rise was only observed for plasma glucose concentrations [Glu] and plasma galactose concentrations [Gal] H istorically considerable attention has been focused on neonatal glucose metabolism because glucose is the major energy substrate for the neonate and because of the relatively high frequency of hypoglycemia in newborns, particularly infants of diabetic mothers (IDMs) and infants with IUGR. Several recent studies, however, have highlighted the importance of carbohydrates other than glucose in fetal and neonatal nutrition. Several sugar alcohols (polyols), such as inositol, sorbitol, and erythritol, are concentrated in embryonic fluid (1) and in both human and ovine fetal plasma (2,3) compared with maternal plasma. Furthermore, inositol may be important in the pathogenesis of neural tube defects in IDMs (4) and prevention of retinopathy and chronic lung disease in preterm infants (5,6). Galactose is an important carbohydrate for energy production in the first few months of life by serving as the main substrate for hepatic glycogen synthesis (7). Several free carbohydrates, oligosaccharides, and sugar alcohols are present in breast milk, adding further support of their potential importance in neonatal nutrition (8).Although most neonatal feeding studies have focused primarily on changes in glucose and insulin concentrations (9,10), there have been no studies of the impact of milk feedings upon the changes in plasma concentrations of other carbohydrates or sugar alcohols. Such studies would be important to determine the roles of these unique carbohydrates in neonatal metabolism and growth and might provide insight into their utilization within the intestine versus the liver and other organs in the body and how such patterns of utilization might reflect underlying abnormal metabolic functions. For example, although galactose is cleared by hepatic first pass metabolism during milk feeding in normal newborns (7,11), this pattern might be quite different in infants with severe IUGR. It has been suspected that fetal hepatic injury might occur in severely IUGR pregnancies because of marked reduction in fetal hepatic blood flow from a reduction in umbilical blood flow and increased shunting of umbilical blood flow away from the fetal liver through the ductus venosus (DV) (12,13). Postnatally, some IUGR infants demonstrate evidence of hepatic injury that m...