The importance of food

摘要

IT HAS BEEN FIRMLY ESTABLISHED THAT LOW MA-ternal intake of folate creates a fetal nutrient deficiency that leads to incomplete development of the fetal nervous system. The critical period for maternal folate intake seems to be the first few weeks of fetal development. Ensuring adequate folate intake during this period is a vexing problem because the fact of pregnancy may not be known even to die modier at this early stage. The confluence of the problem of getting women of childbearing age to eat an adequate amount of folate with the observation that adequate folate helps prevent neural tube defects (NTDs) led to the addition of folic acid to grain foods in the US food supply starting in 1998. This strategy has been effective in getting folate to young potential mothers and also in reducing NTDs.However, the strategy enhances an otherwise nutrient-poor food (refined grain foods are the primary focus of fortification; whole grain foods are naturally rich in folate) and increases folic acid in purified form to the total population.