A research group in Norway investigated if Vitamin D levels in pregnancy had an effect on newborn anthropometric measures and found no association.
An association between newborn anthropometric measurements and chronic diseases such as type-2 diabetes or cardiovascular diseases has been reported. Birth weight and body composition of the newborn also vary substantially among ethnic groups. Vitamin D has been shown to have an important role in bone and other organ development, but it is not yet known how maternal Vitamin D levels in pregnancy affect birth weight of offspring.
A recent article published in the British Journal of Nutrition assessed how Vitamin D levels of the mother during pregnancy affected anthropometric measures of the newborn. Participants were healthy pregnant women with singleton, term pregnancies, recruited between 2008 and 2010. Maternal blood Vitamin D levels were measured at 15 and 28 weeks of gestation. After the first measurement, deficient women were recommended to consult with their physician about supplementation. 51% of the women had Vitamin D deficiency at 15 weeks of gestation and Middle Eastern/North African and Asian participants had higher levels than European women. The mean birth weight also differed between ethnic groups. In models adjusting for maternal age, parity, education, pre-pregnancy BMI, season of birth, gestational age and neonate sex, maternal Vitamin D was significantly associated with birth weight, head circumference, abdominal circumference and ponderal index. However, after adjustment for ethnicity, was no longer any significant association with maternal vitamin D. Furthermore, Asian and Middle Eastern ethnicities were associated with lower birth weight, independently of maternal Vitamin D levels. On the other hand, researchers found a significant interaction between the sex of the neonate and abdominal circumference and sum of skinfolds. With an increase in Vitamin D levels, abdominal circumference increased in girls, while the sum skinfolds increased in boys.
In conclusion, after adjusting for ethnicity, researchers did not find a significant association between newborn measurements and Vitamin D levels in the mother. Further studies are needed to investigate the effect of Vitamin D in the development of specific organs and to study possible sex differences.
Written By: Dr. Fanni R. Eros
