Maternal vitamin D status and its effect on maternal and infant bone health: A systematic review

There are numerous reports of the high prevalence of vitamin D insufficiency in pregnant women living in the United States. Yet the effect of maternal vitamin D status on maternal and infant bone outcomes remains unclear. A systematic review was performed to identify randomized and observational studies reporting maternal vitamin D status and its effect on 1) maternal or 2) infant bone health. Medline, PLOS and Cochrane Reviews were searched for relevant studies. 40 studies were identified and included in this review, including 6 randomized control trials. 23 studies reported maternal (weighted mean 65.8 nmol/L) and/or infant serum 25(OH) vitamin D status as their primary aim. There were consistent reports of a high prevalence (40 to 96 %) of maternal 25(OH)D deficiency and a positive correlation (r=0.55–0.68) between maternal serum and infant cord blood 25(OH)D levels. Maternal vitamin D supplementation (1000IU/d – 20000IU once) studies (n=4) resulted in an increase in maternal serum 25(OH)D and infant cord blood levels. Despite a plethora of research on maternal 25(OH)D status, there is a paucity of studies focused on the effect of maternal vitamin D supplementation on either maternal or neonatal bone. To inform dietary recommendations for pregnant women, the effect of maternal 25(OH)D status on maternal and infant bone outcomes requires further study. Grant Funding Source: United States Department of Agriculture