Multivitamins with 0.4 - 0.8 mg of folic acid are best in birth defect prevention

Periconceptional use of folic acid supplements is effective for the primary prevention of neural-tube defects and is recommended by reproductive health researchers.

Recent research in this area, however, centres on two main debated questions. The first one is whether the use of folic acid alone or folic acid-containing multivitamins is better. The second one is whether high dose of folic acid (e.g. 5 mg) might be better than a daily multivitamin with 0.4 – 0.8 mg of folic acid. This paper by Prof. Andrew E. Czeizel, receiver of 2002 award of US National Council on Folic Acid for Excellence in Research in the Field of Folic Acid and Birth Defects Prevention, presents a study of two trials and a case-control surveillance of congenital abnormalities that involve very large population.

The result is that multivitamins containing 0.4 – 0.8 mg of folic acid were more effective for the reduction of neural-tube defects than high dose of folic acid. Both multivitamins and folic acid can prevent some part of congenital cardiovascular malformations. Only multivitamins were able to reduce the prevalence at birth of obstructive defects of urinary tract, limb deficiencies and congenital pyloric stenosis, while folic acid was effective in preventing some part of rectal/anal stenosis/atresia, and high dose of folic acid had effect in preventing some orofacial clefts. It recommends daily use of multivitamin supplement including 0.4 – 0.8 mg of folic acid for pregnant women to prevent neural-tube defects and some other congenital abnormalities.