Vitamin D Supplementation Myth Debunked by Latest Research

A groundbreaking study undertaken by Queen Mary University of London and the Harvard T.H. Chan School of Public Health, which is the largest to focus on vitamin D supplementation in children, has found that these supplements neither increase bone strength nor prevent fractures in children lacking vitamin D, thereby challenging traditional assumptions about vitamin D's effects on bone health.

The comprehensive clinical trial, performed in association between Queen Mary University of London and the Harvard T.H. Chan School of Public Health, has found that vitamin D supplements do not bolster bone strength or decrease the possibility of bone fractures in children showing signs of vitamin D deficiency. This research contravenes prevalent notions concerning the influence of vitamin D on bone health.

Approximately a third of all children suffer from at least one fracture before they turn 18. This is a significant worldwide health issue, given that fractures during childhood can lead to many years living with disability and/or poor quality of life. The possibility of vitamin D supplements improving bone strength has been progressively gaining more attention, due to vitamin D's role in facilitating bone mineralization. Nevertheless, clinical trials to assess whether vitamin D supplements can prevent bone fractures in children have yet to be carried out up until now.

Joining forces with collaborators in Mongolia, a country grappling with an exceptionally high burden of fractures and widespread prevalence of vitamin D deficiency, the researchers from Queen Mary and Harvard set up a clinical trial to evaluate if vitamin D supplementation could reduce the likelihood of bone fractures or boost bone strength in schoolchildren. The recent study published in the Lancet Diabetes & Endocrinology is the largest ever controlled randomized trial of vitamin D supplementation carried out on children.

Over a three-year period, a total of 8,851 schoolchildren between the ages of 6 and 13 living in Mongolia were given a weekly oral dose of vitamin D supplementation. The supplements were very effective in raising the children's vitamin D levels into the normal range, with 95.5% of participants showing evidence of vitamin D deficiency initially. However, the supplements made no impact on the frequency of fractures or bone strength, as determined through quantitative ultrasound in a subset of 1,438 participants.

The conclusions from the trial are anticipated to make scientists, doctors, and public health experts reconsider the implications of vitamin D supplements on bone health.

Associate Professor at the Harvard T.H. Chan School of Public Health, Dr. Ganmaa Davaasambuu, stated:

“The fact we found no impact from prolonged, ample vitamin D supplementation on fracture risk or bone strength in children deficient in vitamin D is remarkable. In adults, vitamin D supplementation is most effective for preventing fractures when given in conjunction with calcium - the fact we did not offer calcium alongside vitamin D to trial participants maybe why we found no effect from this study.”

Professor Adrian Martineau, Head of the Centre for Immunobiology at Queen Mary University of London, added:

“It's also vital to mention that children who were diagnosed with rickets while being screened for the trial were not included, as it wouldn't have been ethical to offer them a placebo (dummy medication). As such, our findings are only relevant for children with low vitamin D levels who haven't developed bone complications. The role of adequate vitamin D intake for prevention of rickets should not be overlooked, and UK government advice suggesting a daily intake of 400 IU vitamin D continues to be important and should still be adhered to.”