Prenatal vitamins and pediatric ca risk.(DRUGS, PREGNANCY, AND LACTATION)

There is some evidence that the use of vitamins in general and folic acid in particular may inhibit the development of some types of cancer in adults, although the data are not from randomized trials and are debated.

There are also several studies suggesting folic acid may protect against certain pediatric cancers, and a recently reported metaanalysis conducted by Motherisk found that prenatal vitamin use during pregnancy was associated with a reduced risk of some pediatric cancers.

Several years ago, we reported the results of a study in Ontario that found an association between folic acid fortification of flour and a 50% decrease in the prevalence of pediatric neuroblastoma, an apparent protective effect.

We conducted this study after the Pediatric Oncology Group in Ontario asked us if we could identify an environmental explanation for the fewer cases of neuroblastoma in children in Ontario, a trend they first noticed in the late 1990s. This group keeps records of all the pediatric cancers in the province.

The only factor we could identify was that in 1997 and 1998, folic acid fortification of flour became compulsory in Canada, as in the United States, so virtually every citizen, unless they did not eat flour-based products, was exposed to greater levels of folic acid.

We were able to show that indeed, year by year, with the introduction of folic acid fortification of flour, there was a parallel decrease in the number of neuroblastomas diagnosed in young children in Ontario (Clin. Pharmacol. Ther. 2003;74:288-94).

Intrigued by these results, we looked into whether other investigators had arrived at similar observations about multivitamin supplementation and pediatric cancers.