Folic acid versus 5-MTHF in pregnancy
What it found
Folic acid needs to be converted by the liver into its active form, 5-MTHF, before the body can use it.
In some women this conversion is reduced, and the paper suggests 5-MTHF may avoid certain risks.
What they found
Folic acid needs conversion
Folic acid is inactive in the human body and must be converted by the liver into the active molecule 5-MTHF.
What 5-MTHF does
5-MTHF acts as a methyl donor in many metabolic reactions, including turning homocysteine into methionine, making glycine from serine, and making DNA building blocks.
Folate and growth
Folate is fundamental for growth, especially in the embryonic and fetal stages.
Risks with folic acid
In conditions such as megaloblastic anemia, folic acid can conceal megaloblastic anemia caused by vitamin B12 deficiency. It can also pose risks when the liver converts it poorly, for example due to genetic variants or some medicines.
Possible advantage of 5-MTHF
Some of these risks can be avoided by taking 5-MTHF instead of folic acid. Because 5-MTHF does not need activation, it is immediately available to mother and fetus and does not build up in blood when liver conversion is reduced.
What the authors conclude
- They review the advantages and disadvantages of folate supplementation with folic acid versus 5-MTHF, with a focus on maternal and fetal health.
- They note that some risks of folic acid can be avoided by supplementation with 5-MTHF rather than folic acid.
How it was done
Folate is widely accepted to protect against fetal neural tube defects, and folic acid is the main source used in fortified foods and supplements. The authors wanted to compare the advantages and disadvantages of folic acid with 5-MTHF for maternal and fetal health.
What it can’t tell you
- We summarised it from the abstract only.
- This is a review, not a new study in people. It cannot show how folic acid or 5-MTHF affect pregnancy outcomes in a trial.
- The paper does not give numbers or measures of health effects in mothers or babies.
Who paid
- Conflicts
- Declaration of Competing Interest This above unconditional support was funded by Zambon Italia Srl.
The paper
- Title
- Folic acid versus 5- methyl tetrahydrofolate supplementation in pregnancy
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Summarised from
- Abstract only
- Cite
- Ferrazzi E, Tiso G, Di Martino D (2020). Folic acid versus 5- methyl tetrahydrofolate supplementation in pregnancy. European journal of obstetrics, gynecology, and reproductive biology. doi:10.1016/j.ejogrb.2020.06.012PubMed 32868164DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error