Vitamin D may be protective for many kinds of cancer. A Chinese meta-analysis of 25 studies including more than 17,000 cancer patients found that those who had higher levels of vitamin D in their bodies at diagnosis were more likely to survive longer.
The clearest links were with breast cancer, lymphoma and colon cancer, but there were also suggestive associations between higher vitamin D blood levels and better survival from lung, stomach and prostate cancer. Leukemia and melanoma may also be less likely to kill patients whose vitamin D at diagnosis is adequate.
[Journal of Clinical Endocrinology & Metabolism, July, 2014]
This is not the first time that adequate vitamin D levels have been associated with better survival from serious health problems. Not long ago, a different meta-analysis revealed that people with low levels of circulating vitamin D were 14 percent more likely to die from cancer, and 35 percent more susceptible to cardiovascular death. To learn more about vitamin D, including information on the most common doses of supplements and the possible risks of taking too much, you can consult our Guide to Vitamin D Deficiency.