San Francisco, CA—A new study reported at the 2015 American Society of Cancer Oncology (ASCO) Gastrointestinal Cancers Symposium in San Francisco shows that patients metastatic colorectal cancer who had high levels of vitamin D in their bloodstream prior to treatment with chemotherapy and targeted drugs survived longer on average than those who did not. Previous studies have shown that vitamin D may be able to play a role in cancer inhibition, but according to study author Kimmie Ng, MD, MPH, from the Dana-Farber Cancer Institute, this particular study is the largest to date testing metastatic colorectal cancer and vitamin D.

The study data was taken from 1,043 patients when they enrolled in a phase 3 trial of three different drug combinations for newly diagnosed, advanced colorectal cancer. At that time, researchers measured blood levels of 25-hydroxyvitamin D, a substance produced in the liver from vitamin D. The patients were then divided into five groups based on the level of vitamin D they had in their body prior to treatment, ranging from an average of 8 ng/mL in the lowest group to an average of 27.5 ng/mL in the highest group. The overall average for the patients was 17.2 ng/mL, which is below the Endocrine Society’s definition of vitamin D deficiency at 20 ng/mL.

On average, the groups with the highest levels of vitamin D survived 33% longer than the lower groups, roughly 32.6 months vs. 24.5 months. High vitamin D levels were also associated with longer time to disease progression in the study. Due to the fact that high levels of vitamin D are often signs of a healthy lifestyle with good nutrition and physical activity, researchers controlled for these factors in the study. Even with these measures in place, Ng observed that the relationship between vitamin D and extended survival was still prevalent.

Published in WholeFoods Magazine, March 2015 (online 1/23/15)