Question & Answer

During pregnancy, is taking 5-MTHF supplements as effective as taking folic acid supplements in reducing neural tube defects?

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  • The neural tube, which is responsible for the development of the brain and spine in the embryo, closes during the first 28 days of pregnancy. If this closure does not happen, neural tube defects such as ‘spina bifida’ can develop.
  • Research has shown that folic acid supplementation during early pregnancy substantially reduces the likelihood of the development of neural tube defects.
  • Both 5-methyltetrahydrofolate (5-MTHF) and folic acid are different forms of ‘Vitamin B9’.
  • Claims have been made that taking 5-MTHF during pregnancy is as effective as taking folic acid for reducing the likelihood of neural tube defects.
  • We found no high-quality evidence that 5-MTHF supplementation is as effective as folic acid in reducing neural tube defects during pregnancy.

Things to Remember


  • Drafted by: KM Saif-Ur-Rahman, Evidence Synthesis Ireland and Cochrane Ireland, University of Galway.
  • Reviewed by: Prof Declan Devane, College of Medicine, Nursing and Health Sciences, HRB-Trials Methodology Research Network, Evidence Synthesis Ireland & Cochrane Ireland, University of Galway.
  • Topic Advisor: Frank Moriarty, Senior Lecturer in Pharmacy at the School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland and visiting research fellow at The Irish Longitudinal Study on Ageing (TILDA).
  • Public and patient advisor: Deirdre Mac Loughlin, Public and Patient Involvement in research (PPI) advisor, PPI Ignite, University of Galway.
  • Journalistic advisor: Claire O’Connell, Contributor to The Irish Times, writing about health, science and innovation.

Conflict of Interest Statement: The authors have no financial or other conflicts of interest for this health claim summary.