The use of folic acid goes beyond preventing macrocytic anemia and birth defects. It has value for preventing cardiovascular disease and birth (neural tube) defects. Folic acid has a role in the production of DNA, may therefore have a role in cancer prevention. Two recently published large preliminary studies (Nutr Rev. 1999 Oct;57(10):314-321) show that having a high enough blood level of folatecan reduce the risk of both pancreatic and breast cancer, as can moderately increasing folic acid intake in the diet (especially vegetables) and vitamin supplements.
Protection from pancreatic cancer by folic acid appears to be especially true for male smokers. Women who regularly consume a moderate amount of alcohol seem to benefit from folic acid as a preventative for breast cancer. The expanding role of folic acid in cancer prevention has major public health implications, but more research is needed.