Taking vitamin D could increase your lifespan, reported The Daily Mail. It said that researchers had pooled the results of 18 individual trials of vitamin D supplements and found that taking them reduced the risk of death by 7%. Vitamin D is “being credited with reducing the risk of death from any causes,” the Mail said.
The reports are based on a good quality systematic review. Although this study has shown that vitamin D supplementation may reduce the risk of death over a certain period, it does not tell us how much longer people might live if they take vitamin D, or what causes of death vitamin D might be preventing. The authors of this research have called for further randomised controlled trials to confirm their conclusions.
Philippe Autier and Sara Gandini from the International Agency for Research on Cancer in France, and the European Institute of Oncology in Italy carried out this research. No external funding for this study was reported. It was published in the peer-reviewed medical journal, Archives of Internal Medicine.
This was a systematic review and meta-analysis of the results from randomised controlled trials of vitamin D supplementation.
The researchers searched databases of scientific and medical literature in November 2006 for any randomised controlled trials comparing vitamin D supplementation (either vitamin D2 or D3) to control (no treatment or a placebo) for any health condition, that reported how many people died in each group.
The researchers then pooled the data on deaths using complex statistical methods, to see whether there were any differences between the vitamin D and control groups. They also used statistical methods to see whether results varied depending on dose of vitamin D received, whether participants also received calcium supplements, or how long participants were followed up for.
The researchers identified 18 randomised controlled trials, which enrolled 57,311 people and followed them up for about six years on average. People in the vitamin D groups in these trials received an average daily dose of 528 units of vitamin D; in most trials, people were taking vitamin D to reduce their risk of a fracture.
Overall, the researchers found that vitamin D supplementation reduced the relative risk of death by 7% compared with the control group. This result did not seem to vary with vitamin D doses, whether people received calcium supplements, or how long participants were followed up for.
The researchers concluded that taking “ordinary” doses of vitamin D reduce overall mortality. They suggested that large placebo-controlled randomised trials looking specifically at mortality should be conducted to confirm these findings.
This was a well-conducted systematic review and meta-analysis, whose results seem reliable. When interpreting the study some points should be considered:
The evidence about the benefits of vitamin D is getting stronger and there is little evidence of harm. More research is urgently needed.
However, I have decided to start taking vitamin D, as well as more exercise by walking my extra 3000 steps every day; these steps I call my vital steps because they are of importance to my life and health.