Review

There is general consensus that folic acid supplementation during the periconceptional period substantially reduces the risk of neural tube defects. This reduction in risk has led many health organisations to issue recommendations for women to take 0·4 mg of synthetic folic acid daily in addition to consuming food folate from a varied diet.1 Three public-health strategies exist for reaching the recommended daily dose required for eff ective prevention of defects: (1) women take supplements with folic acid in combination with a healthy diet; (2) foods are fortifi ed with synthetic folic acid on a voluntary basis; and (3) a staple food is fortifi ed on a mandatory basis. After a short overview of the preventive potential of folic acid the main aim here is to review successes and failures of these three methods. Special emphasis is placed on population-base