Pregnant women are advised to consume 600mg dietary folate equivalents daily from all food sources.
Dietary folate equivalents adjust for the difference in bioavailability of food folate
compared with synthetic folic acid. One dietary folate equivalent is equal to 1mg food folate, which is equal to 0.6mg folic acid derived from supplements and fortified foods taken with meals.
14
Women who have had an infant with a neural tube defect should consult with
their health care provider regarding the recommendation to take 4,000 mg
folic acid daily before and throughout the first trimester of pregnancy.
22
An association between the lack of periconceptual use of vitamins or supplements containing folic acid with an excess risk for birth defects due to diabetes mellitus
23
highlights ongoing research.