Cochrane review

Vitamin D supplements fail to improve bone density

REVIEWERS have found vitamin D supplements fail to improve bone density in healthy children with adequate vitamin D levels.

The review of six randomised trials, including 1000 children and adolescents, found healthy children randomised to vitamin D supplementation for at least three months had no statistically significant improvement in bone density at the hip, lumbar spine, forearm or of the whole body compared with those given placebo.

However, the authors, from the University of Tasmania, said the findings suggested children with vitamin D deficiency might derive a “clinically significant” benefit from vitamin D supplementation.

Vitamin D supplementation in children with low serum vitamin D levels (35 nmol/L) showed a 2.6% improvement in total body bone density from baseline compared with controls.

The authors said previously trials had suggested supplementation could maximise peak bone mass density in children, and may have had potential for reducing the impact of age-related bone loss in later life.

Speed cameras reduce injures and save lives

SPEED cameras do significantly reduce road traffic injuries and deaths, Australian reviewers say.

A review of 35 studies, including seven from Australia, found average speeds decreased by up to 15% in the presence of speed cameras in comparison to areas devoid of speed cameras.

Car crash rates also decreased by almost half in these areas, and the frequency of crashes involving fatal and/or serious injuries decreased by 11 per cent. 

The reviewers, from the University of Queensland, said: “While there is variation in the results, the overall findings is clear – speed cameras do reduce injuries and deaths.”

Cochrane Database of Systematic Reviews 2010, Issue 10