In this study involving 304 subjects diagnosed with colon cancer, those whose blood levels of vitamin D were in the top 25% were twice as likely to survive as those in the lowest 25%.
The authors conclude, "Among patients with colorectal cancer, higher prediagnosis plasma 25(OH)D levels were associated with a significant improvement in overall survival. Further study of the vitamin D pathway and its influence on colorectal carcinogenesis and cancer progression is warranted."
With cancer treatments being toxic and costing hundreds of thousands of dollars, and vitamin D being safe and cheap, I recommend people with cancer take 4,000 units of vitamin D a day now, instead of waiting 20 years for these studies to be done!
"Circulating 25-hydroxyvitamin d levels and survival in patients with colorectal cancer," Ng K, Meyerhardt JA, et al, J Clin Oncol, 2008; 26(18): 2984-91