Taking vitamin D supplements could help cancer patients live longer, according to new research.
Vitamin D carries significant benefits beyond contributing to healthy bones. Researchers found taking a daily supplement for at least three years could cut the risk of dying of all cancers by 13%. However, there was no evidence that taking vitamin D pills could prevent the disease in the first place.
Dr Tarek Haykal, lead author on the study and an internal medicine resident physician at Michigan State University and Hurley Medical Centre said: "Vitamin D had a significant effect on lowering the risk of death among those with cancer, but unfortunately it didn't show any proof that it could protect against getting cancer."
Every two minutes someone in the UK is diagnosed with cancer and the disease accounts for over a quarter of deaths in the country.
To reach their conclusions, the Michigan team looked at data from more than 79,000 patients in multiple studies that compared the use of vitamin D to placebo over at least three years.
"The difference in the mortality rate between the vitamin D and placebo groups was statistically significant enough that it showed just how important it might be among the cancer population," Haykal said.
These findings are promising - not least because vitamin D supplements carry minimal side effects - but more research is needed before we understand how much of the vitamin is needed, why it has this effect of longevity, and for how much longer supplements might extend someone's life.
"All we can say is that at least three years of taking the supplement is required to see any effect. We know it carries benefits with minimal side effects. There's plenty of potential here," concluded Haykal.
The research is published in the Journal of Clinical Oncology.