It's become widely accepted that mothers taking folic acid during pregnancy can help reduce the risk of several birth defects. But a new study at the University of Toronto finds a correlation between pre-natal multivitamins containing folic acid and the decreased risk of several pediatric cancers: leukemia, brain tumors, and neuroblastoma (a malignant tumor in nerve tissue).

This report in Clinical Pharmacology and Therapeutics found that taking a multivitamin with folic acid before and during early pregnancy could reduce the risk of leukemia by 36%, childhood brain tumors by 27%, and neuroblastoma by 47%.

It was estimated in 2005 that, each year, 9,500 children in the United States are diagnosed with cancer, and that 25-35% of those cases are leukemia. The researchers claim that "based on these data, one can estimate that maternal multivitamin supplementation may prevent 900 cases of pediatric leukemia and 300-400 cases of pediatric brain tumors annually in the United States."

While the research team suspects that folic acid may be the preventive agent, they found that the current data wasn't definitive. Nevertheless, they suggest that, "[as]women who are considering pregnancy are generally advised to supplement with folic acid, the results from this study suggest that supplementation with a folic acid-containing multivitamin may be a preferred method."