Researchers at the American Society of Cancer Oncology report that clinical trial participants with newly diagnosed colorectal cancer fared better if they had higher blood levels of vitamin D.
The patients were enrolled in studies of anti-cancer drugs, and their blood levels of 25-hydroxyvitamin D were measured at the beginning of the studies. Those with the lowest levels, around 8 nanograms/mL, survived for an average of two years. Those with the highest levels, roughly 27 ng/mL, lived an additional eight months, on average.
The research does not show that taking extra vitamin D would have an impact on cancer survival, but it has inspired the investigators to start such a study. The benefit of high vitamin D levels held up even after statistical adjustment for physical activity, diet and obesity.
[ASCO Gastrointestinal Cancers Symposium, San Francisco, Jan. 12, 2015]
To learn more about vitamin D, supplements, sunshine and 25-hydroxyvitamin D levels, see our Guide to Vitamin D Deficiency.