This Vitamin Might Be Undervalued For Fetal Brain Development & It's Easy To Get
If you've ever been pregnant or tried to conceive, you've heard the advice: take folic acid.
It's one of the most consistent recommendations in prenatal care, credited with cutting the risk of neural tube defects (serious birth defects affecting the brain and spinal cord) by about 50%.
About the study
Folic acid (vitamin B9) has been a cornerstone of prenatal care for decades, but the exact reason it prevents neural tube defects has never been fully understood.
To investigate, researchers studied frog embryos (a standard model in developmental biology whose early growth closely mirrors that of human embryos) using CRISPR/Cas9 to switch off specific genes and track how each one affected neural tube development.
Folic acid works through a vitamin A connection
The researchers found that folic acid doesn't appear to protect a developing baby's brain and spinal cord directly. Instead, it seems to help the body produce retinoic acid, an active form of vitamin A that's essential for the neural tube to close properly in early pregnancy.
To test this, the team blocked an enzyme needed to make retinoic acid. When they did, folic acid no longer prevented neural tube defects. But when they gave embryos retinoic acid directly, normal development was restored, even without folic acid.
This suggests that retinoic acid is the molecule doing the protective work, while folic acid helps ensure the body can make enough of it.
The researchers also found that without enough retinoic acid, the cells that form the neural tube grow too quickly and in a disorganized way, making it harder for the tube to close properly.
Their findings suggest this vitamin A pathway plays a key role in keeping early development on track.
What this means if you're pregnant or trying to conceive
This research doesn't change current folic acid recommendations. The CDC still advises that anyone who could become pregnant take 400 micrograms of folic acid daily, and that guidance remains fully supported.
At mindbodygreen, we like to be more specific and choose methylfolate, the highly bioactive form of B9.
But this study does offer a clearer picture of how folic acid works, and a suggestion that vitamin A availability may matter more to early neural development than previously understood.
That said, this was an animal study, and more research is needed before any changes to human prenatal nutrition guidelines would be warranted.
A few practical notes:
- Keep taking methyfolate before and during early pregnancy: This study reinforces existing guidance rather than revising it.
- Get vitamin A from food and prenatal vitamins: Most prenatals already include it, and a varied diet with leafy greens, eggs, and orange and yellow vegetables provides it naturally.
- Skip extra vitamin A supplements: Too much preformed vitamin A (the kind in supplements, not plant foods) can be harmful during pregnancy. Unless your provider recommends it, don't go beyond what's in your prenatal. Good nutrition during and after pregnancy matters well beyond the first trimester.
The takeaway
Scientists have long known folic acid reduces the risk of neural tube defects; now there's a clearer picture of why.
The mechanism runs through vitamin A, with folic acid activating an enzyme that produces a form of it essential for early brain and spinal cord development. Current prenatal guidance stays the same, but this research opens the door to more targeted approaches down the line.