We found that supplementation of supplementation of pregnany women with cholecalciferol 1000 IU/day from 14 weeks' gestation until delivery of the baby does not lead to increased offspring neonatal BMC overll.
Link to Publication: http://www.sciencedirect.com/science/article/pii/S2213858716000449
Cooper C, et al. Maternal gestational vitamin D supplementation and offspring bone health (MAVIDOS): a multicentre, double-blind, randomised placebo-controlled trial. Lancet Diabetes Endocrinology. 2016. pii: S2213-8587(16)00044-9.