Vitamin D, also known as the sunshine vitamin, helps regulate the amount of calcium and phosphate in the body - minerals that are essential for bones, teeth, and muscle health.

Researchers from the University of Southampton and University Hospital Southampton (UHS) in the UK showed that an increase in women’s intake of vitamin D supplements during pregnancy can boost bone mineral density in the children’s mid-childhood.

Increased maternal vitamin D supplements spiked calcium and other minerals in the kids’ bones. This made their bones stronger and less likely to break.

Dr Rebecca Moon, NIHR Clinical Lecturer in Child Health at the University of Southampton said that the “early intervention represents an important public health strategy”.

In the paper, published in The American Journal of Clinical Nutrition, she added that the strategy can boost “children’s bones and reduce the risk of conditions like osteoporosis and fractures in later life”.

For the study, the team examined more than 1,000 pregnant women. Then they divided the women into those one taking an extra 1,000 International Units per day of vitamin D, and the other taking a placebo daily. Further, they followed 454 children aged six to seven to see the effects on bone health continued into mid-childhood.

The beneficial effect on children’s bones was similar at ages four and six to seven.

Previously, the Southampton researchers demonstrated that maternal vitamin D supplementation substantially reduced the chances of babies up to a year old suffering from atopic eczema.