Those with with the highest levels of vitamin D in their blood are more likely to survive the disease, a study shows.
The study is the first to look at blood levels of vitamin D in bowel cancer patients and link it to their survival rates.
Vitamin D is produced by exposure to sunlight and also comes from dietary sources.
The research at The University of Edinburgh tested blood samples from almost 1600 patients after surgery for bowel cancer.
The greatest benefit of vitamin D was seen in patients with stage 2 disease, at which the tumour may be quite large but the cancer has not yet spread.
Researchers found that three quarters of the patients with the highest vitamin D levels were still alive at the end of five years, compared with less than two thirds of those with the lowest levels.
The results show that vitamin D is associated with a much better chance of cancer survival, although the nature of this relationship is not clear from this study.
The study’s authors aim to set up a clinical trial to test whether taking vitamin D tablets in combination with chemotherapy can improve bowel cancer survival rates.
Measuring vitamin D levels in bowel cancer patients could also provide a useful indication of prognosis, the scientists say.
Professor Malcolm Dunlop, of the Medical Research Council Human Genetics Unit at the University of Edinburgh, said: “Our findings are promising but it is important to note that this is an observational study. We need carefully designed randomised clinical trials before we can confirm whether taking vitamin D supplements offers any survival benefit for bowel cancer patients.”
The research is published in the Journal of Clinical Oncology