Background In this study we aimed to investigate the relationship between maternal and neonatal 25(OH)D levels.

Methods The subjects were 58 mothers and their newborns who were born between February 2012 and April 2012. Blood specimens were obtained within 72 h of birth and from mothers. Serum 25(OH)D concentrations were measured. Vitamin D deficiency was defined as serum concentrations ≤20 ng/mL.

Results The mean gestational age and birth weight of preterm infants were 33.06 ± 2.2 weeks and 2125.4 ± 546 g and for term infants were 38.84 ± 1 weeks and 3470.3 ± 451 g, respectively. Sociodemographic characteristics of mothers were not significantly different between groups.

Twelve percent of infants born before 32 completed weeks, 16% infants born between 32–36 weeks and 28% of term infants had vitamin D deficiency. Vitamin D deficiency was found in 27% mothers of preterm infants and 42% mothers of term infants.

Conclusion Vitamin D receptors plays an important role in calcium absorption and bone metabolism. In the literature there are reports that vitamin D deficiency during pregnancy had adverse gestational outcomes including risk of pre-eclampsia, gestational diabetes. The mean vitamin D levels were normal in infants whereas their mothers had low levels of vitamin D. When we consider that all mothers in the study received vitamin D supplements, we should give appropriate vitamin D prophylaxis during pregnancy. Also we should give adequate vitamin D supplementation to the infants without any delay.