As early as 1941, it was observed that people living at higher latitude were at higher risk of dying of cancer. In the 1980’s and the 1990’s, several reports surfaced revealed that living at higher latitude and being at higher risk of vitamin D deficiency increased risk of developing and dying of cancers of the colon, rectum, prostate, breast, ovary. More recently, vitamin D deficiency has been associated with increased risk of developing many other cancers including cancer of the esophagus, pancreas and leukemia. Women in the Women’s Health Initiative that evaluated the effect of calcium and vitamin D on risk of developing colorectal cancer revealed that women who were vitamin D deficient and followed for eight years had a 253% increase risk of developing colorectal cancer. These data are also supported by a recent observation by Lappe et al who reported that women ingesting 1,100 IU of vitamin D and 1,200 milligrams of calcium a day reduced overall risk of developing cancer by almost 70%.
Grant, W.B., Lower vitamin-D production from solar ultraviolet-B Irradiance may explain some differences in cancer survival rates. Journal of the National Medical Association. 2006; 98(3):357-64.
Gorham ED, Garland CF, Garland FC, Grant WB, Mohr SB, Lipkin M, Newmark HL, Giovannucci E, Wei M, Holick MF. Vitamin D and prevention of colorectal cancer. J Steroid Biochem Mol Biol 2005; 97(1-2):179-194.
Holick, M.F. 2006. High prevalence of vitamin D inadequacy and implications for health. Mayo Clin. Proc. 81(3):353-373.
Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr 2007; 85(6):1586-1591.