Folic acid to prevent neural tube defects: Success and controversies

Abstract

The impact of folic acid food fortific ation in Canada is described and current controversies are discussed. • Mandatory fortification of many cereal products was implemented in 1998. • Level of fortification is set at 0.15 mg/100 g for fl our and cornmeal. • The estimated average additional intake is approximately 150 m g/day. • Folate deficiency in the population was virtually eliminated. • The overall frequency of neural tube defects was reduced by a factor of 2 and geographical variation almost disappeared. • A decrease in the birth frequency of congenital cardiovascular malformations, of Wilms' tumor and neuroblastoma in children, and of stroke mortality in adults was also observed. • Currently, there is no consensus regarding the folic acid supplement dose to recommend for women of childbearing age, the safety and potential effectiveness of increasing folic acid fortification level, and the potential impact and feasibility of fortifying food with vitamin B12.