the effectiveness of dietary fortification with folic acid (fa) on the prevention of congenital anomalies has already been analyzed by several investigators in different regions of world. these fa dietary supplementation programs aimed at the primary prevention of congenital anomalies had already been regulated and implemented in three of the 10 south american countries: argentina, brazil, and chile. on 52 malformations type, statistically significant reductions in birth prevalence rates after fortification were observed for neural tube defects (ntd) in the three south american countries. the stronger effect of folic acid fortification on spina bifida than on anencephaly and cephalocele has already been reported in other parts of the world, such as usa, canada, and south africa. no prevalence rate reduction was observed for congenital heart diseases, oral clefts, and other anomalies, the reduction of which after folic acid fortification has been occasionally reported by other studies. the safety and the effectiveness of the fortification program must be continued to be monitored overtime to detect reductions in other congenital anomalies with lower frequencies than dtn.