Folic acid and autism across 52 studies in people
What it found
Across 52 studies involving 10,429 people with autism, most had low folic acid intake.
Folic acid taken by mothers was not linked to autism risk in their children.
What they found
Studies in people
Low folic acid intake
Most people with autism in these studies did not take in enough folic acid. This finding stayed consistent when earlier research was updated.
Mothers taking folic acid
No link was found between mothers taking folic acid during pregnancy and autism risk in their children.
Folic acid as treatment
People with autism showed improvements in communication, social skills, and behaviour after taking folic acid supplements. The authors note that autism is complex and varies from person to person.
Other findings
Blood markers measured
The studies checked blood levels of folic acid, vitamins B6 and B12, homocysteine, and methionine in people with autism.
What the authors conclude
- They say more high-quality research and clinical trials with careful designs are still needed on this topic.
How it was done
Autism affects communication, social skills, and behaviour. Scientists looked into folic acid because this vitamin matters for brain health.
Two reviewers searched for research linking folic acid to autism and found 2,389 studies. They fully read 52 studies that met their criteria, covering 10,429 people diagnosed with autism. They looked at vitamin intake, blood levels, supplement treatments, and folic acid exposure during pregnancy.
What it can’t tell you
- We summarised it from the abstract only.
- These studies looked back at existing data, so they can only show links rather than prove that low folic acid causes autism symptoms.
- Improvements seen after taking folic acid do not guarantee the same results for every person with autism.
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 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error