...
By Daniella Gray
Reporter
0
Share
Newsweek is a Trust Project member
See more of our trusted coverage when you search.Prefer Newsweek on Googleto see more of our trusted coverage when you search.
Taking folic acid and multivitamin supplements during pregnancy may significantly lower the risk of autism spectrum disorder (ASD) in children, according to a study conducted by Australian researchers.
The team carried out a so-called umbrella review—a high-level analysis that evaluates evidence from multiple systematic reviews and meta-analyses—to determine whether prenatal vitamins play a role in autism prevention.
After screening 1,388 scientific reviews and narrowing the pool to eight high-quality analyses, the researchers examined data from 101 primary studies involving more than three million participants.
Read More on Family & Parenting
The findings concluded that women who took folic acid or multivitamin supplements during pregnancy had a 30 percent lower risk of having a child diagnosed with ASD compared with those who did not supplement.
When the supplements were analyzed separately, the results remained strong. Prenatal multivitamins were linked to a 34 percent reduction in autism risk, while folic acid alone was linked to a 30 percent reduction.
...
“There is very sound rational for women planning a pregnancy to take additional folic acid," said Professor Helen Truby, a professorial research fellow in nutrition and dietetics at The University of Queensland, who was not involved in the study.
“Folic acid is critical for the fetus neural tube development during the first trimester of pregnancy,” she continued. “This scientific evidence underpins recommendations for folic acid supplementation pre-conception and during the first trimester. However, the role of folic acid in ASD risk remains to be proven.”
Autism spectrum disorder affects up to one percent of children worldwide and is associated with challenges in social communication, behavior and co-occurring conditions such as anxiety, ADHD and sleep difficulties.
While genetics play a major role, several environmental factors—particularly prenatal nutrition—are considered modifiable contributors to risk.
“This paper does highlight that pregnancy is time when the diet quality is crucial. That is, ensuring that the diet contains sufficient range of micronutrients to meet the needs of both the mother and to ensure that the growing baby has all the micronutrients they need for optimal growth and development," Truby said.
"This may include the use of multivitamins—including folic acid—supplements especially for women who do not have access to a safe, adequate and secure food supply.”
Previous studies on prenatal supplements and autism risk have identified protective effects, while others reported no significant association. Differences in how supplements were measured, variations in dosage and timing, and inconsistent diagnostic methods for ASD made it difficult to draw firm conclusions.
By pooling and comparing results across multiple high-quality reviews, the umbrella analysis provides stronger evidence than any single study, according to the authors.
Using a standardized grading system, they found the protective effects of folic acid and multivitamins to be “highly suggestive.”
Dr. Linda Gallo, a senior lecturer in the School of Health at the University of the Sunshine Coast, who was also not involved in the study, warned that the findings on multivitamin use should be interpreted cautiously.
Multivitamins affect various aspects of maternal health, but their benefits are hard to assess due to varying formulations.
“For example, higher-dose or high-frequency supplementation has been linked to increased risks such as gestational diabetes, and one of the most common prenatal supplements in Australia contains double the dose of folic acid that is most associated with the protective effects reported in this new study,” Dr. Gallo explained.
“These issues require careful consideration before recommending prolonged multivitamin use for all pregnant women. There is certainly a place for targeted supplementation but it is unlikely to be necessary for everyone, and not for the entire duration of pregnancy.”
Melanie McGrice, an advanced accredited practising dietitian with a Masters degree in nutrition, explained that certain groups have higher or more complex folate requirements and may not receive what they need from a standard supplement alone.
"My concern is particularly for those who conceive without planning and miss the critical early window for folate, women with higher-than-average folate needs, such as those with a BMI over 30, malabsorptive conditions, or who smoke and individuals who do not metabolise folic acid efficiently and may require a different form of folate or a tailored dose," she said.
To keep ASD rates in check, McGrice said a proactive approach is needed. She added: "Making dietitian consultations a routine part of preconception and early pregnancy care would help ensure women receive individualised folate guidance rather than relying on a one-size-fits-all prenatal.
"The modest cost of personalised nutrition care has the potential to save the government millions in long-term ASD-related health and support services and, more importantly, give children the best possible start to life."
Do you have a tip on a health story that Newsweek should be covering? Do you have a question about eco-friendly plates? Let us know via science@newsweek.com.
Reference
Abate, B. B., Tusa, B. S., Sendekie, A. K., Temesgen, D., Mekuria, K., Alamaw, A. W., Azmeraw, M., Zemariam, A. B., Kitaw, T. A., Kassaw, A., Abebe, G. K., Tilahun, B. D., Yilak, G., Adisu, M. A., Dachew, B. … Dachew, B. (2025). The association between maternal prenatal folic acid and multivitamin supplementation and autism spectrum disorders in offspring: An umbrella review. PLOS ONE. https://doi.org/10.1371/journal.pone.0334852
View 0 Comments
Submit Correction
View Editorial & AI Guidelines