A Scottish study of almost 5,000 people suggests that an increased intake of vitamin B6 from diet and supplements may reduce the risk of colorectal cancer by 19%.
There are ~ 945,000 new cases of colorectal cancer every year. The new case-control study involved 2,028 hospital-based colorectal cancer (CRC) patients and 2,722 population-based controls. The lead author, Evropi Theodoratou, noted that "Moderately strong inverse and dose-dependent associations in the whole sample were found between CRC risk and the intake of dietary and total vitamin B6." He also noted that this result has been supported by other studies as well.
Other nutrients are also important. Writing in the Journal of Nutrition (Vol. 137, pp. 2701-2708), Tufts researchers found that moderate deficiency of folate, riboflavin, and vitamins B6 and B12 together may also promote the risk of DNA damage and increase the risk of colorectal cancers. In addition, other studies have suggested that folate deficiency alone may promote the risk of colorectal cancer.
I find that the best effect is obtained by getting all of the B vitamins in a balanced formula (such as the Energy Revitalization System vitamin powder), as this supplies them to the body in a balanced manner. High doses of the individual nutrients alone may cause more harm than good.
E. Theodoratou, S.M. Farrington, A. Tenesa, G. McNeill, R. Cetnarskyj, R.A. Barnetson, M.E. Porteous, M.G. Dunlop, H. Campbell. Dietary Vitamin B6 Intake and the Risk of Colorectal Cancer. Cancer Epidemiology Biomarkers & Prevention. 1st January 2008, Volume 17, Pages 171-182, doi: 10.1158/1055-9965.EPI-07-0621