Mothers who took a vitamin D supplement during pregnancy were more likely to have children with greater bone density at age seven, according to a new study led by the University of Southampton and University Hospital Southampton. Bone density scans revealed that children whose mothers took a vitamin D supplement during pregnancy had a greater calcium and mineral density, reducing fracture risk.
 
The findings, published in the American Journal of Clinical Nutrition, reinforce those of a 2009 study called MAVIDOS, which recruited over 1,000 pregnant women. In that two-arm study, pregnant women received either a placebo tablet or 1,000 extra IU per day of vitamin D.
 
Previous research assessed the children’s bone health at four years of age, and the results showed that the child’s bone mass was greater in children born to mothers who took greater amounts of vitamin D during pregnancy.
 
The latest study was designed to evaluate if these effects continued into mid-childhood. The team followed up with 454 children between six and seven years old, born to mothers who took part in the study. The results confirmed that the beneficial effect on children’s bones was similar in the present day as it was when the children were around four years old.
 
“This early intervention represents an important public health strategy,” said Dr. Rebecca Moon, NIHR clinical lecturer in child health at the University of Southampton, and lead author of the study. “It strengthens children’s bones nad reduces the risk of conditions like osteoporosis and fractures later in life.”
 
“These findings add to the important knowledge generated through the MAVIDOS trial,” said Nicholas Harvey, professor of rheumatology and director of the university’s Lifecourse Epidemiology Center, and project lead. “We extend our heartfelt thanks to all the mothers and children involved. Their contributions have advanced our understanding of vitamin D supplementation and its role in supporting strong and healthy bones.”