According to a Cochrane Systematic Review released on October 6th, yesterday vitamin D supplements when given to healthy children with normal vitamin D levels does not improve bone density at the hip, lumbar spine, forearm or in the body as a whole. Experts believe that bone density is a major determinant of bone strength and measures the amount of bone mineral present at different sites. A healthy bone density prevents future onset of osteoporosis - a condition where bones are weak, brittle and fracture easily.
According to lead researcher Dr Tania Winzenberg, from the Menzies Research Institute Tasmania, Hobart, “By measuring bone density, you can assess how well an intervention such as vitamin D supplementation improves bone health.”
For the study they looked at existing literature for randomized controlled trials that had compared giving children vitamin D supplements with giving placebo. They found six studies that together involved 343 participants receiving placebo or dummy medicine and 541 receiving vitamin D. All participants had taken vitamin D or the placebo for at least three months and were aged between one month and 19 years old. The authors wrote, “Vitamin D supplementation had no statistically significant effects on total bone mineral content, hip bone mineral density (BMD) or forearm BMD.” There was a trend (p=0.07) to a small effect on lumbar spine BMD. The supplements had little effect whether given at high or low doses.
Dr Winzenberg said, “Vitamin D supplementation had no statistically significant effects on bone density at any site in healthy children. There was, however, some indication that children who had low levels of vitamin D in their blood might benefit from supplementation… We now need randomized controlled studies focused on vitamin D deficient children to confirm if vitamin D supplements would help this particular group.”
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