FOLATE LEVELS AND NEURAL-TUBE DEFECTS - IMPLICATIONS FOR PREVENTION

Using data from a recent case-control study, a woman's risk of having a child with a neural tube defect (NTD) was found to be associated wit h early pregnancy red cell folate levels in a continuous dose-response relationship. These findings were used to calculate the reduction in NTD cases that would be expected under two different strategies to rai se folate levels. Targeting high-risk individuals has a small effect o n the population prevalence but can substantially change an individual 's risk. Targeting the population produces a small change in individua l risk but has a large effect on the population prevalence. Supplement ation of high-risk women would be the most efficient method to impleme nt the high-risk strategy, while food fortification would be preferabl e for the population approach. The current guidelines for the preventi on of NTD are for an increased folio acid intake of 0.4 mg per day. Th is would result in a 48% reduction in NTDs, which may be near optimal. The two intervention strategies should be considered complementary in prevention of NTDs.