Do maternal diets low in folic acid serve as environmental factors affecting autism? 

Yes, there is growing evidence that maternal diet, folic acid & autism may be connected, particularly when folic acid levels are insufficient during early pregnancy. A folate-deficient maternal diet is considered a potential environmental factor that can influence autism risk due to its critical role in early brain and neural tube development. 

Folic acid, a B vitamin, is essential for DNA synthesis and repair. During pregnancy, it’s particularly important for supporting cell division and the formation of the brain and spinal cord. A lack of it can disrupt these processes at a vital developmental stage.

How Low Folic Acid in Maternal Diet May Affect Autism Risk 

Here are two ways a folate-poor maternal diet might contribute to autism or related environmental effects: 

Impaired neural development in early pregnancy 

Low folic acid intake in the first trimester may lead to incomplete neural tube closure and altered brain development. Studies have linked such deficiencies with an increased likelihood of autism-related traits in children. 

Interaction with genetic susceptibility 

In families already predisposed to autism, inadequate folate may compound developmental risk by interfering with normal gene expression. This gene–nutrient interaction is a focus in emerging autism research. 

Understanding the connection between maternal diet, folic acid & autism underscores the importance of prenatal nutrition. Visit providers like Autism Detect for personal consultations and further guidance on screening and support. 

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to Environmental Factors. 

Lucia Alvarez, MSc

Author

Lucia Alvarez is a clinical psychologist with a Master’s in Clinical Psychology and extensive experience providing evidence-based therapy and psychological assessment to children, adolescents, and adults. Skilled in CBT, DBT, and other therapeutic interventions, she has worked in hospital, community, and residential care settings. Her expertise includes grief counseling, anxiety management, and resilience-building, with a strong focus on creating safe, supportive environments to improve mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy. 

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.