Vitamin D3 and Colon Cancer

It always amazes me when, after a multi-million dollar study, the medical profession “declares an ah-ha moment” about something that alternative doctors have been touting for decades. This study on Vitamin D and cancer is another example. Initial data from the SUNSHINE trial were reported at a prior meeting of the American Society of Clinical Oncology, and the final data are now reported in JAMA.

This large-scale, clinical trial evaluating whether high-dose vitamin D₃ supplementation could benefit patients with colorectal cancer (CRC) is being planned on the back of positive final data from a smaller-scale study, which found that high-dose vitamin D₃ supplements can help to extend progression-free survival (PFS) in CRC patients undergoing chemotherapy. Newly published results from the Phase II SUNSHINE trial comparing the effects of low-dose and high-dose vitamin D₃ showed that higher doses of the vitamin extended CRC PFS from 11 months to 13 months. Patients in the high-dose cohort were also 36% less likely to have disease progression or death during the 22.9 months follow up. The trial wasn’t powered to determine benefits of vitamin supplementation on overall survival.

“To our knowledge, this study is the first completed randomized clinical trial of vitamin D supplementation for treatment of advanced or metastatic colorectal cancer,” said Kimmie Ng, MD, MPH, director of clinical research at the Dana-Farber Cancer Institute’s Gastrointestinal Cancer Center, and corresponding author. “The results of our trial suggest an improved outcome for patients who received vitamin D supplementation, and we look forward to launching a larger trial to confirm these exciting and provocative findings,” added Charles Fuchs, MD, MPH, formerly of Dana-Farber, and senior author of the study, who is now director of Yale Cancer Center.

The researchers report the SUNSHINE trial data in a paper titled, “Effect of high-dose vs standard-dose vitamin D₃ supplementation on progression-free survival among patients with advanced or metastatic colorectal cancer. The SUNSHINE randomized clinical trial.”

Experimental evidence suggests that vitamin D has anti-neoplastic activity, and observational studies have indicated that high levels of vitamin D can reduce colorectal cancer risk and also improve survival among CRC patients, the authors stated. A prospective analysis of Phase III data from a trial evaluating more than 1000 patients with metastatic CRC enrolled in a Phase III trial evaluating chemotherapy plus biological agents also found that patients with higher blood levels of 25-hydroxyvitamin D—the best indicator of vitamin D status—had much better overall survival and PFS. “However, observational studies are not able to discern whether higher 25-hydroxyvitamin D levels play a causal role in improving survival, are simply a surrogate of better health, or a reflection of more favorable disease,” the researchers pointed out.

In a separate paper published in the same issue of JAMA (“Effects of vitamin D supplementation on relapse-free survival among patients with digestive tract cancers”), a research team headed by scientists at the Jikei University School of Japan, reported results from the AMATERASU trial, which found no benefit of postoperative vitamin D₃ supplementation on the relapse-free survival of 417 patients with digestive tract cancers.

We have always recommended our cancer patients to try to keep their blood Vitamin D levels between 50-150 and to take a Vitamin D3 along with the other fat soluble vitamins (A, D, and K as MK7). See HERE for a product we use with 5000iu Vitamin D along with these other nutrients. Taking 1-2 capsules per day is usually adequate.