Abstract
Objectives
Maternal vitamin D status has gained substantial attention as a modifiable contributor to offspring musculoskeletal health, yet there is a paucity of trial-derived data to corroborate effects of prenatal or postpartum vitamin D supplementation on offspring bone mass accrual. Among maternal-infant pairs in Bangladesh, we aimed to examine the hypothesized causal association of early life vitamin D exposure with musculoskeletal health in childhood.
Methods
In a double-blind dose-ranging trial of maternal vitamin D3 supplementation (Maternal Vitamin D for Infant Growth Trial), healthy pregnant women (n = 1300) were recruited at 17–24 weeks’ gestation and randomly assigned to receive a prenatal; postpartum regimen of 0;0,4200;0,16,800;0,28,000;0 or 28,000;28,000 IU vitamin D3/week until 26 weeks postpartum. In a follow-up study of offspring at 4 years of age (n = 642), bone mineral content (BMC) and bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry. Between-group differences were assessed by independent t-tests (28,000 IU/week prenatally vs placebo) and linear regression (each vitamin D treatment group vs placebo) with bootstrapping (1000 replications).
Results
Whole-body (WB), total-body-less-head (TBLH) and head-only BMC were similar in the combined high-dose prenatal and placebo groups (mean difference [95% CI] = 6.81g [−8.70, 22.32], 0.61g [−10.90, 12.13] and 1.71g [−3.54, 6.96], respectively). None of the mean values for WB or TBLH BMC or BMD in each vitamin D group were different from placebo (P > 0.05 for all comparisons). Although head BMD was slightly greater in offspring of women assigned to the 28,000;28,000 IU regimen compared to placebo (mean difference [95% CI] = 0.024g/cm2 [0.0009, 0.047], P = 0.042), the effect was attenuated and no longer significant upon adjustment for child height, weight, and sex (P = 0.11).
Conclusions
In a population with high prevalence of vitamin D deficiency, our findings do not support the use of maternal prenatal vitamin D supplementation, with or without postpartum supplementation, for improvement of child BMC or BMD at 4 years of age.
Funding Sources
Canadian Institutes for Health Research and the Bill and Melinda Gates Foundation.
Effects of maternal vitamin D3 status on quality characteristics of pork batters in offspring pigs during cold storage
