Vitamin D Supplement During Pregnancy Does not Help Baby’s Bone Development

Baby's bone development does not largely benefit from vitamin D supplements taken by their mother during pregnancy, a new British study said.

Previous studies show that higher vitamin D in mothers during pregnancy helps their babies to have a greater bone density. Thus, guidelines in the United Kingdom recommend pregnant women to take vitamin D supplement, Health 24 reported.

On the other hand, the American College of Obstetricians and Gynaecologists says that the supplement is only recommended to soon-to-be mothers who have vitamin D deficiency.

The new study was done to more than 1,100 British women, 14-17 weeks pregnant and has low to normal levels of vitamin D. Half of the women took 1,000 International Unit vitamin D capsule each day until their baby was born and the other took a placebo. The result: there were no significant differences in bone mass between each group's babies.

However, among babies who were born in the winter, those whose mothers took the vitamin D supplements had a greater bone mass compared to the other group, as reported by UPI.

Researchers also found that the mothers in placebo group who gave birth in the winter had their vitamin D level dropped between 14-34 weeks of pregnancy, but not the mothers who took vitamin D.

That suggests that the mothers who will have their last stages of pregnancy during the winter should take vitamin D supplement as lack of sunshine results to lower vitamin D level.

"Babies' bones strengthen during the last stages of pregnancy. Since sunlight is our most important source of vitamin D, mothers' levels of vitamin D tend to drop from summer to winter, and babies born in the winter months tend to have lower bone density than those born during the summer," said study co-author Nicholas Harvey, a professor of rheumatology and clinical epidemiology at the University of Southampton.

Therefore, only babies that are born during winter will benefit from vitamin D supplementation to help counteract low level of vitamin D caused by lack of sunlight.