There's good news for those of you who have taken the proactive step to make sure your vitamin D level is optimized. Several recent studies demonstrate vitamin D can have a significantly beneficial impact on your cancer risk, both in terms of preventing cancer and in the treatment of cancer.

Vitamin D Reduces Cancer Mortality

In the first of these studies,1,2 which included 25,871 patients, vitamin D supplementation was found to reduce the risk for metastatic cancer and death by 17%. The risk was reduced by as much as 38% among those who also maintained a healthy weight.

This was a really poorly done study as they only gave participants 2,000 IUs a day and never measured their blood levels. Had there been no improvement, I would not have been surprised, but the fact is it still reduced metastatic cancer and death by 17%, and they found significant benefit among those who were not obese.  

This is pretty extraordinary but not as good as epidemiological studies that show a 50% to even 78% reduction in vitamin D sufficient people, as suggested in a study further below. That said, UPI reported the results saying:3

"The benefits of vitamin D3 in limiting metastases — or disease spread to other organs — and severity was seen across all cancers, and was particularly prominent among study participants who maintained a healthy weight …