Effects of prenatal and/or postnatal (maternal and/or child) folic acid supplementation on the mental performance of children.

It has been suggested that a deficiency in folic acid during early, critical central nervous system development may result in persistent cognitive and behavioral effects. The purpose of this systematic review was to evaluate evidence regarding whether folic acid supplementation during pregnancy and early life influences mental performance outcomes in children. The following electronic databases were searched through December 2009 for studies relevant to mental performance and folic acid: MEDLINE, EMBASE and The Cochrane Library; additional references were obtained from reviewed articles. Only randomized controlled trials (RCTs) were included. Of 8 RCTs identified, only 2 met the inclusion criteria. Both studies involved periconceptional, multivitamin-containing, folic acid supplementation. Evidence from these 2 RCTs suggests that such supplementation does not affect the postnatal mental development of infants at a mean age of 11 mo, the developmental quotient (DQ) at 2 y of age, or the intelligence quotient (IQ) and Goodenough man drawing test quotient (DrQ) at 6 y of age. We conclude that the use of multivitamin-containing folic acid supplementation during pregnancy is associated with no benefit to the mental performance of children. These findings should be interpreted with caution due to the very limited number of studies included in this systemic review.