Folic acid and autism: what 52 studies show
What it found
Most people with autism in these studies did not get enough folic acid.
Taking folic acid during pregnancy was not linked to autism risk in children.
What they found
Studies in people
Low folic acid intake
Most people with autism in the included studies did not get enough folic acid. This finding stayed the same as in an earlier review.
Folic acid in pregnancy
Taking folic acid during pregnancy was not linked to the risk of autism in children.
Folic acid supplements
Some studies reported improvements in communication, socialization and behavior in people with autism who took folic acid. The authors note that autism varies greatly from person to person.
What the authors conclude
“No association was found between maternal exposure to folic acid and the risk of ASD in their children.”
Also in their conclusions
- They say that the evidence of insufficient folic acid intake in most individuals with ASD remains consistent.
- They stress that it is crucial to consider the individuality and complexity of ASD.
- They call for more high-quality research and clinical trials with rigorous methods.
How it was done
Folic acid matters for brain health, so researchers wanted to see how it relates to autism spectrum disorder.
They reviewed 52 studies that together included 10,429 people diagnosed with autism. The studies looked at intake and blood levels of folic acid, vitamin B6 and vitamin B12, plus folic acid treatments and folic acid exposure during pregnancy.
What it can’t tell you
- We summarised it from the abstract only.
- The review cannot prove that low folic acid intake causes autism or that folic acid supplements improve autism symptoms.
- The studies included were varied, so the results may not apply to everyone.
Who paid
- Authors work at
- Hospital de Clínicas de Porto Alegre, Brazil; National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Brazil
The paper
- Title
- Folic acid and autism: updated evidences
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Vasconcelos C, Perry IS, Gottfried C, Riesgo R, Castro K (2025). Folic acid and autism: updated evidences. Nutritional neuroscience. doi:10.1080/1028415X.2024.2367855PubMed 38968136DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error