Vitamin D supplements do not prevent bone fractures in children

A major clinical trial led by Queen Mary University of London and the Harvard T.H. Chan School of Public Health has found that vitamin D supplements do not increase bone strength or prevent bone fractures in children with vitamin D deficiency. The findings challenge widely held perceptions relating to the effects of vitamin D on bone health.

The potential for vitamin D supplements to improve bone strength has attracted growing interest in recent years, based on vitamin D’s role in promoting bone mineralisation. However, clinical trials designed to test whether vitamin D supplements can prevent bone fractures in children have not previously been conducted.

Working with partners in Mongolia, a setting with a particularly high fracture burden and where vitamin D deficiency is highly prevalent, researchers from Queen Mary and Harvard conducted a clinical trial to determine if vitamin D supplementation would decrease risk of bone fractures or increase bone strength in schoolchildren. The study, published today (1 December) in Lancet Diabetes & Endocrinology, is the largest randomised controlled trial of vitamin D supplementation ever conducted in children.

The trial findings are likely to prompt scientists, doctors and public health specialists to re-consider the effects of vitamin D supplements on bone health.

Dr Ganmaa Davaasambuu, said “The absence of any effect of sustained, generous vitamin D supplementation on fracture risk or bone strength in vitamin D deficient children is striking. In adults, vitamin D supplementation works best for fracture prevention when calcium is given at the same time – so the fact that we did not offer calcium alongside vitamin D to trial participants may explain the null findings from this study.”

Reference: Vitamin D supplements do not prevent bone fractures in children; The Lancet Diabetes & Endocrinology; DOI:10.1016/S2213-8587(23)00317-0