Folic acid and prevention of neural tube defects.

QUESTION: Now that flour and pasta have been fortified with folic acid in Canada, do I still need to recommend folic acid supplements to my patients who are of child-bearing age? If I should recommend supplements, when should I recommend them, and what is an appropriate dose? ANSWER: Non-pregnant women should consume 400 microg of folic acid daily, and pregnant women should consume 600 microg of folic acid daily. Mean intakes of folate in Canada before fortification were around 200 microg/d or less. Fortification increased intake of folic acid by up to 100 microg/d. You should discuss the importance of folic acid with your patients who are planning pregnancy; it is recommended that a folic acid supplement or prenatal multivitamin containing at least 400 microg of folic acid be consumed daily. The upper limit for folic acid is 1 mg/d. Women in intermediate- to high-risk categories for neural tube defects, such as a previous neural tube defect-affected pregnancy, should take 4 to 5 mg of folic acid daily.