Previous studies involving the role of folic acid supplements and breast cancer have produced conflicting information with some studies showing that it protects against breast cancer, others have suggested that taking high amounts of folic acid may increase the risk of developing breast cancer. The level and amount of folic acid consumed in North America has increased dramatically in the past 15 years and women in particular are routinely advised to take folic acid supplements as part of their post and prenatal care.
“This is a critically important issue because breast cancer patients and survivors in North America are exposed to high levels of folic acid through folic acid fortification in food and widespread use of vitamin supplements after a cancer diagnosis,” Dr. Kim lead author of the study said. “Cancer patients and survivors in North America have a high prevalence of multivitamin and supplement use, with breast cancer patients and survivors having the highest prevalence.”
The dose tested was 2.5 to five times the daily requirement.
Shaidah Deghan Manshadi, Lisa Ishiguro, Kyoung-Jin Sohn, Alan Medline, Richard Renlund, Ruth Croxford, Young-In Kim. Folic Acid Supplementation Promotes Mammary Tumor Progression in a Rat Model. PLoS ONE, 2014; 9 (1): e84635 DOI: 10.1371/journal.pone.0084635