Mothers-to-be who take a multivitamin with folic acid before and during pregnancy may be protecting their children from several types of cancer, according to a new study published in Clinical Pharmacology & Therapeutics (2007, vol. 5, no. 81).

Canadian researchers analyzed data from seven studies of multivitamins and pediatric cancers published between 1994 and 2005. They found that children whose mothers had taken a prenatal multivitamin with folic acid had a 27 percent reduced risk for pediatric brain tumors, a 39 percent lower risk for leukemia, and a 47 percent reduced risk for neuroblastoma.

Leukemia accounts for nearly one-third of all cancers in children younger than 15, making it the most common childhood cancer. Malignant brain and spinal cord tumors are the second most common. Neuroblastoma is the number-one cancer in infants, and the fourth most common in children.

Researchers aren't certain which component of the multivitamin offers protection against cancer. However, getting 400 mcg per day of folic acid before and during pregnancy has been shown to drastically reduce neural tube birth defects, which affect the brain and spinal cord. Iron is another important nutrient for expectant mothers; it helps both mother's and baby's blood carry oxygen.