Vitamin D supplementation in pregnancy: Postnatal effects on preterm infant

Vitamin D plays an important role in calcium homeostasis. It has also pro-apoptotic, antiinflammatory and immunmodulatory effects. Especially preterm infants are in great risk of vitamin D deficiency. A prospective observational study was conducted to investigate the effects of maternal 25-OH D vitamin supplementation on postnatal life of preterm infant. Pregnants admitted to our hospital between April 2017 and October 2017 with preterm labor were included in the study. Twenty nine pregnants were enrolled. Only two patients were taking vitamin D prophylaxis regularly during pregnancy. Two pregnants were discarded because of having stillbirth. None of the pregnants had sufficient vitamin D level. The mean vitamin D level of all pregnants was 10.83 ng/ml (4.2-23.1). Twelve pregnants (44.5%) had hypocalcemia. Fifteen pregnants having preterm birth were included in control group. Only one of 15 preterm infants had sufficient vitamin D level. Twelve pregnants attended with preterm labor were included in study group. Patients in study group got vitamin D treatment (50.000 IU oral, weekly). In study group, ten pregnants had no more risk of preterm delivery after vitamin D and tocolytic treatment and were discharged. It was determined that the vitamin D level in cord blood samples of preterm infants was related to maternal vitamin D level (p<0.01). The vitamin D level of the infants was found to be higher than maternal vitamin D level (p<0.01) and their correlation was high (0.755). In control group, the relationship between gestational age and maternal vitamin D level was not statistically significant (p>0.05). The length of stay in neonatal intensive care unit of 15 preterm infants was not related to neonatal or maternal vitamin D levels (p>0.05). This study shows that vitamin D deficiency in pregnancy is common. It was shown that vitamin D level of the infant is directly related to maternal vitamin D level and vitamin D may play role in decreasing the risk of preterm delivery. Key words: 25-OH vitamin D, neonatal morbidity, prematurity.