Bowel cancer patients with high levels of vitamin D in their blood are more likely to survive the disease, according to a recent study.

Researchers from the University of Edinburgh in the United Kingdom found that people with the highest levels of Vitamin D have half the risk of dying compared with those with the lowest levels.

"The study is the first to correlate total blood levels of vitamin D in bowel cancer patients after their diagnosis -- which includes that produced after exposure to sunlight and that obtained from dietary sources -- with their long term survival prospects," researchers wrote.

For the study, the research team tested blood samples from nearly 1,600 patients after surgery for bowel cancer.

Based on their findings, the greatest benefit of vitamin D was seen in patients with stage 2 disease, at which the tumor 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 which the end of five years, compared with less than two thirds of those with the lowest levels.

The findings suggest 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.

"Our findings are promising but it is important to note that this is an observational study. We need carefully designed randomized clinical trials before we can confirm whether taking vitamin D supplements offers any survival benefit for bowel cancer patients," researcher Malcolm Dunlop said in a statement.

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.

They said measuring vitamin D levels in bowel cancer patients could also provide a useful indication of prognosis.