Folic Acid and Neural Tube Defects: The Current Evidence and Implications for Prevention

  1. Gregory Bock and
  2. Joan Marsh
  1. N. J. Wald

Published Online: 28 SEP 2007

DOI: 10.1002/9780470514559.ch12

Ciba Foundation Symposium 181 - Neural Tube Defects

Ciba Foundation Symposium 181 - Neural Tube Defects

How to Cite

Wald, N. J. (2007) Folic Acid and Neural Tube Defects: The Current Evidence and Implications for Prevention, in Ciba Foundation Symposium 181 - Neural Tube Defects (eds G. Bock and J. Marsh), John Wiley & Sons, Ltd., Chichester, UK. doi: 10.1002/9780470514559.ch12

Author Information

  1. Department of Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, St. Bartholomew's Hospital Medical College, Charterhouse Square, London EC1M 6BQ, UK

Publication History

  1. Published Online: 28 SEP 2007

ISBN Information

Print ISBN: 9780471941729

Online ISBN: 9780470514559

SEARCH

Keywords:

  • folic acid;
  • neural tube defects;
  • dose-response relationship;
  • food fortification;
  • excretion

Summary

The results of the MRC Vitamin Study have established the specific role of folk acid in the prevention of neural tube defects. Folic acid supplementation (4 mg/day) at the time of conception reduced the recurrence rate by about 70%. Evidence from observational studies and the Hungarian randomized trial (that used 0.4-0.8 mg/day supplemental folk acid) indicates that a similar level of prevention can be achieved among women who have not already had an affected pregnancy and that this may be achieved with a lower dose of folic acid. The medical implications of these results are important. (1) Women planning a pregnancy should take folk acid supplements. (2) Because a large proportion of pregnancies are unplanned and many of those that are planned will occur in women who will not have taken folic acid supplements, a complementary general public health strategy is needed, based on dietary advice and food fortification designed to achieve the benefit with adequate safety. (3) Any public health prevention strategy needs to be monitored for efficacy and possible harm. (4) Research is needed on the dose-response relationship between folk acid and neural tube defect prevention and the mechanism of action.