Alternative Health Blog

In a randomized, placebo-controlled study involving 5,442 women 42 years of age or older, with pre-existing cardiovascular disease or three or more coronary risk factors, supplementation with 2.5 mg/d folic acid, 50 mg/d vitamin B6, and 1 mg/d vitamin B12 for a period of 7.3 years, supplementation with these vitamins in women over the age of 65 was found to be associated with a 38% reduced risk of breast cancer and a 25% reduced risk of other invasive cancers. On the other hand, no significant difference in risk was found in the study population as a whole. The study began in 1998, after folic acid fortification of grains became mandatory in the United States, suggesting that even women in the placebo group were ingesting folic acid through consumption of grain products as part of their diet. Additional research is needed to further investigate the possibility that combined supplementation with folic acid, vitamin B6, and vitamin B12 may reduce the risk of breast cancer and other invasive cancers in women over the age of 65.
 
Reference:
"Effect of combined folic acid, vitamin B6, and vitamin B12 on cancer risk in women: a randomized trial," Zhang SM, Cook NR, et al, JAMA, 2008; 300(17): 2012-21.