Pregnancy Vitamin D Supplementation Linked to Better Bone Health in Children: Study Finds

The findings from the exploratory post-hoc analysis, published in The American Journal of Clinical Nutrition, indicate a clear association between maternal cholecalciferol use and improved bone health outcomes in their children.

Bone mineral density is a key marker of bone strength and overall skeletal health, and the research suggests that sufficient vitamin D during pregnancy could serve as a public health strategy to combat childhood bone-related disorders. Vitamin D plays a vital role in calcium absorption, which is critical for developing strong and healthy bones.

The Maternal Vitamin D Osteoporosis Study (MAVIDOS) trial provided evidence that gestational cholecalciferol supplementation positively influenced offspring bone mineral density (BMD) at age 4. Establishing whether this effect persists into later childhood is essential to determine if maternal vitamin D supplementation could be an effective public health strategy for improving long-term bone health. To this end, Rebecca J Moon, MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton General Hospital, Tremona Road, Southampton, United Kingdom, and colleagues explored whether gestational vitamin D supplementation leads to increased offspring BMD at ages 6–7 years through a post-hoc analysis of data from the existing trial.

In the MAVIDOS randomized controlled trial, pregnant women under 14 weeks of gestation with singleton pregnancies and serum 25-hydroxyvitamin D levels between 25–100 nmol/L at three UK hospitals (Southampton, Sheffield, and Oxford) were randomly assigned to receive either 1000 IU/day cholecalciferol or a placebo. This supplementation began between 14 and 17 weeks of gestation and continued until delivery. Children born at term to mothers recruited in Southampton were invited to participate in the childhood follow-up at ages 4 and 6–7 years.

The children underwent dual-energy X-ray absorptiometry (DXA, Hologic Discovery) scans of the whole body excluding the head (WBLH) and lumbar spine. Measurements assessed bone area, bone mineral content (BMC), bone mineral density (BMD), and bone mineral apparent density (BMAD). Linear regression analysis was applied to compare the two groups while adjusting for potential confounding factors such as age, sex, height, weight, duration of breastfeeding, and vitamin D use at ages 6–7 years.

The analysis uncovered the following findings:

• A total of 454 children were followed up at ages 6–7 years, with 447 having a usable DXA scan.
• Gestational cholecalciferol supplementation was associated with higher whole-body less head bone mineral content (WBLH BMC), bone mineral density (BMD), bone mineral apparent density (BMAD), and lean mass compared to the placebo group.
• Specifically, WBLH BMC was 0.15 SD higher, BMD was 0.18 SD higher, and BMAD was 0.18 SD higher. Additionally, lean mass was 0.09 SD higher in the cholecalciferol group.
• The effects of gestational cholecalciferol supplementation on bone outcomes were consistent at ages 4 and 6–7.

"We showed that pregnant women who took 1000 IU/day of cholecalciferol during pregnancy showed higher offspring bone mineral density (BMD) and lean mass in mid-childhood compared to those who received a placebo, according to an exploratory post-hoc analysis," the researchers wrote.

"These findings highlight that vitamin D supplementation during pregnancy could serve as a key public health strategy to enhance bone health in children," they concluded.

Reference:

Moon RJ, D' Angelo S, Curtis EM, Ward KA, Crozier SR, Schoenmakers I, Javaid MK, Bishop NJ, Godfrey KM, Cooper C, Harvey NC; MAVIDOS Trial Group. Pregnancy vitamin D supplementation and offspring bone mineral density in childhood follow-up of a randomized controlled trial. Am J Clin Nutr. 2024 Nov;120(5):1134-1142. doi: 10.1016/j.ajcnut.2024.09.014. Epub 2024 Sep 19. PMID: 39306330; PMCID: PMC11600048.