A major study suggests that vitamin D supplements could lower the risk of heart attacks and other serious cardiovascular events in people over 60. The research, published in The BMJ, involved over 21,000 Australians and is the largest randomised controlled trial of its kind.
Participants aged 60 to 84 were given either a monthly vitamin D supplement or a placebo for up to five years. The results showed a 9% reduction in major cardiovascular events in the vitamin D group, with heart attack risk falling by 19%. However, no significant difference was observed for stroke.
The absolute risk difference was small: 6.6% of the placebo group experienced a major cardiovascular event compared with 6% in the vitamin D group. The researchers calculated that 172 people would need to take supplements to prevent one such event.
Lead author Dr. Rachel Neale from the QIMR Berghofer Medical Research Institute noted that previous randomised trials had not found a link, possibly due to differences in design. She said the findings suggest earlier conclusions that vitamin D does not affect cardiovascular risk were 'premature'.
The study's limitations include its focus on an Australian population, meaning results may not apply elsewhere. Nonetheless, the trial had high adherence and near-complete data on outcomes. Vitamin D is known to be important for bone and muscle health, and UK guidelines recommend supplementation in autumn and winter.
