The current study is the largest of its kind ever conducted in North America.
In their study, researchers looked at children diagnosed with childhood brain tumors and compared them with children without brain tumors. They then interviewed the mothers of both groups of kids about their vitamin use.
Daily vitamin and mineral use in the month before pregnancy -- and in each trimester -- was associated with a 30-40% reduction in risk of brain tumors, reports lead author Andrew F. Olshan, PhD, epidemiologist with the University of North Carolina in Chapel Hill. His study appears in the September issue of Epidemiology.
While it was not clear which specific vitamins or minerals are responsible for the protective effect, Olshan says his study does suggest a "beneficial association."
Among nutrients researchers believe might reduce the incidence of childhood cancers: folic acid, and vitamins C and A. Folic acid is also known to prevent birth defects such as spina bifida.