Plasma vitamin A concentrations were measured in cord blood samples from 56 infants of gestational ages < 33 weeks. Outcome was followed prospectively. Mothers' dietary habits and use of multivitamins during pregnancy were evaluated by means of a questionnaire. Vitamin A concentrations less than 1.05 micromol/l (low) were measured in 22, but levels below 0.7 micromol/l (deficient) only in two cases. The concentrations were not correlated with the infants' gestational ages. Infants with low concentrations were significantly more often multiplets compared to those with normal levels and the vitamin A concentrations of the multiplets were significantly lower than those of the singletons. The outcome measures used and the mothers' dietary habits and multivitamin use were similar in cases with low and normal vitamin A concentrations. Multiple gestation seems to be correlated with low plasma vitamin A concentrations in preterm infants at birth, and a complete assessment of vitamin A status to detect possible deficiency might be indicated in these cases.