There have been no successful randomized controlled trials (RCT) of vitamin D supplementation and reduced risk of colorectal cancer, primarily due to using too little vitamin D (400 IU/day) in many studies12.
However, one RCT with post-menopausal women living in Nebraska using 1450 mg/day of calcium and, for some, 1100 IU/day of vitamin D, found a 77% reduced risk of all-cancer incidence between the ends of the first and fourth years, of which 35% was attributed to vitamin D; those taking only calcium had a 40% risk reduction, which was not statistically significant3.
Page last edited: 07 September 2011
- Grant, W. B. Garland, C. F. A critical review of studies on vitamin D in relation to colorectal cancer. Nutr Cancer. 2004; 48 (2): 115-23.
- Wactawski-Wende, J. Kotchen, J. M. Anderson, G. L. Assaf, A. R. Brunner, R. L. O’Sullivan, M. J. Margolis, K. L. Ockene, J. K. Phillips, L. Pottern, L. Prentice, R. L. Robbins, J. Rohan, T. E. Sarto, G. E. Sharma, S. Stefanick, M. L. Van Horn, L. Wallace, R. B. Whitlock, E. Bassford, T. Beresford, S. A. Black, H. R. Bonds, D. E. Brzyski, R. G. Caan, B. Chlebowski, R. T. Cochrane, B. Garland, C. Gass, M. Hays, J. Heiss, G. Hendrix, S. L. Howard, B. V. Hsia, J. Hubbell, F. A. Jackson, R. D. Johnson, K. C. Judd, H. Kooperberg, C. L. Kuller, L. H. LaCroix, A. Z. Lane, D. S. Langer, R. D. Lasser, N. L. Lewis, C. E. Limacher, M. C. Manson, J. E. Calcium plus vitamin D supplementation and the risk of colorectal cancer. N Engl J Med. 2006 Feb 16; 354 (7): 684-96.
- Lappe, J. M. Travers-Gustafson, D. Davies, K. M. Recker, R. R. Heaney, R. P. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr. 2007 Jun; 85 (6): 1586-91.