Maternal Vitamin D Osteoporosis Study (MAVIDOS) study trial conducted in United Kingdom hospitals (Southampton, Sheffield and Oxford) - a randomized control trial where pregnant females <14 weeks with singleton pregnancy were randomly assigned to 1000 IU/d cholecalciferol or placebo from 14-17 weeks gestation until delivery.

Total of 454 children were followed up till 6-7 years from Southampton, out of which 447 had a usable DXA (Dual Energy Absorptiometry) scan of whole-body-less-head, Bone Mineral Content (BMC), Bone Mineral density (BMD), Bone Mineral Apparent Density (BMAD) and lean mass compared with placebo.

They also observed that pregnant women given extra vitamin D were more likely to have spontaneous vaginal delivery and demonstrated positive effect of gestational cholecalciferol supplementation on offspring bone mineral density at age of 4 yrs.

The study was published in American Journal of Clinical Nutrition suggests that supplementation of Vitamin D in pregnancy may be an important population health strategy to improve bone health.