Children whose mothers had taken extra vitamin D during pregnancy continue to have stronger bones at age seven, say researchers from University of Southampton and University Hospital Southampton (UHS).
In their recent study, bone density scans revealed that children born to mothers who were given vitamin D supplements during pregnancy have greater bone mineral density in mid-childhood – their bones containing more calcium and other minerals, making them stronger and less likely to break.
The findings, published in The American Journal of Clinical Nutrition, reinforce the importance of vitamin D supplementation in pregnancy as a public health strategy, said the researchers.
Vitamin D regulates the amount of calcium and phosphate in the body – the minerals that are so essential for bones, teeth and muscle health
The analysis was led by Dr Rebecca Moon, NIHR Clinical Lecturer in Child Health at the University of Southampton, reports News-Medical.net.
Early study
In 2009, researchers had launched the Maternal Vitamin D Osteoporosis Study (MAVIDOS), recruiting more than 1 000 women from Southampton, Oxford and Sheffield.
During their pregnancy, the women were randomly allocated to two groups: one group took an extra 1 000 International Units per day of vitamin D. the other took a daily placebo tablet. The pregnant women, and the doctors and midwives looking after them, did not know which group they were in.
Previous research assessed the children's bone health at four years of age, with results showing that bone mass was greater in children born to mothers who had had vitamin D supplementation during pregnancy than those who had not.
In this newest study, the researchers investigated whether the effects on bone health continued into mid-childhood. The team followed up with 454 children aged six and seven, all born to mothers who took part in Southampton.
The results confirmed that the beneficial effect on children’s bones was similar at ages four and six to seven.
Pregnant women in the UK are now routinely advised to take vitamin D supplements.
The Southampton research team belong to the MRC Lifecourse Epidemiology Centre (MRC LEC) and the NIHR Southampton Biomedical Research Centre (BRC).
The MAVIDOS trial has helped the Southampton researchers understand possible mechanisms linking maternal vitamin D supplementation to offspring bone mass. In 2018 they demonstrated that the vitamin D supplementation led to changes in the activity of genes forming part of the vitamin D pathway.
In 2022, they found taking the supplements during pregnancy could substantially reduce the chances of babies up to a year old suffering from atopic eczema.
They also observed that pregnant women given extra vitamin D were more likely to have a spontaneous vaginal delivery, or “natural” delivery.
Study details
Pregnancy vitamin D supplementation and offspring bone mineral density in childhood: Follow-up of a randomised controlled trial
Rebecca Moon, Stefania D’ Angelo, Elizabeth Curtis et al.
Published in American Journal of Clinical Nutrition in November 2024
Abstract
Background
Findings from the Maternal Vitamin D Osteoporosis Study (MAVIDOS) trial demonstrated a positive effect of gestational cholecalciferol supplementation on offspring bone mineral density (BMD) at age 4 y. Demonstrating the persistence of this effect is important to understanding whether maternal vitamin D supplementation could be a useful public health strategy to improving bone health.
Objectives
We investigated whether gestational vitamin D supplementation increases offspring BMD at ages 6–7 y in an exploratory post-hoc analysis of an existing trial.
Methods
In the MAVIDOS randomised controlled trial, pregnant females <14 wk’ gestation with a singleton pregnancy and serum 25-hydroxyvitamin D 25–100nmol/l at 3 United Kingdom hospitals (Southampton, Sheffield, and Oxford) were randomly assigned to either 1000 IU/d cholecalciferol or placebo from 14 to 17-wk gestation until delivery. Offspring born at term to participants recruited in Southampton were invited to the childhood follow-up at ages 4 and 6–7 y. The children had a dual-energy X-ray absorptiometry (DXA, Hologic discovery) scan of whole-body-less-head (WBLH) and lumbar spine, from which bone area, bone mineral content (BMC), BMD, and bone mineral apparent density (BMAD) were derived. Linear regression was used to compare the 2 groups adjusting for age, sex, height, weight, duration of consumption of human milk, and vitamin D use at 6–7 y.
Results
A total of 454 children were followed up at ages 6–7 y, of whom 447 had a usable DXA scan. Gestational cholecalciferol supplementation resulted in higher WBLH BMC [0.15 SD, 95% confidence interval (CI): 0.04, 0.26], BMD (0.18 SD, 95% CI: 0.06, 0.31), BMAD (0.18 SD, 95% CI: 0.04, 0.32), and lean mass (0.09 SD, 95% CI: 0.00, 0.17) compared with placebo. The effect of pregnancy cholecalciferol on bone outcomes was similar at ages 4 and 6–7 y.
Conclusions
Supplementation with cholecalciferol 1000 IU/d during pregnancy resulted in greater offspring BMD and lean mass in mid-childhood compared with placebo in this exploratory post-hoc analysis. These findings suggest that pregnancy vitamin D supplementation may be an important population health strategy to improve bone health.
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