Autism Spectrum Disorder (ASD) is a complex neurological condition that impacts social, communicative, and behavioral development. This study investigates the relationship between the dietary habits of pregnant women and the development of ASD in their children, focusing on folic acid (vitamin B9) supplementation. Previous studies suggest that folic acid is essential for neural tube closure during embryonic development, but its excess may be related to an increased risk of autism. The study uses a qualitative methodology and a comprehensive literature review, analyzing articles published between 2017 and 2024 in databases such as SciELO, PubMed, Google Scholar, and Web of Science. The literature review highlights the importance of epigenetic regulation in the neurological development of ASD, influenced by adequate levels of folic acid during pregnancy. However, there is a significant gap in the complete understanding of this relationship, especially regarding the interaction of several nutrients and their impacts on neurodevelopment. In conclusion, although folic acid supplementation is an essential public health measure to prevent neural tube defects, careful monitoring is crucial to avoid potential risks of autism. The research highlights the need for further studies to elucidate the exact mechanisms and identify reliable biomarkers that can aid in early diagnosis and preventive interventions to improve health outcomes in children at risk of developing ASD.