Folinic Acid for Impaired Folate Metabolism to Improve Communication Deficits in Children with Autism Spectrum Disorder

The purpose of this review is to evaluate the efficacy of folinic acid supplementation in addressing communication deficits in children with autism spectrum disorder (ASD). ASD is characterized by persistent deficiency in social communication and interaction, accompanied by restricted and repetitive patterns of behavior. Communication impairments are a core challenge in ASD and remain difficult to treat. Although there is no confirmed etiology, emerging evidence suggests that a subset of children with ASD may have underlying abnormalities in folate metabolism. Folate receptor alpha autoantibodies (FRAAs) are immunoglobulins that interfere with folate metabolism. When present, they can disrupt the transfer of folate across the blood-brain barrier, leading to folate deficiency. This may play a role in the development of core symptoms of ASD, including impaired language. Folinic acid, a bioavailable form of folate, has shown promise in addressing these deficits. A comprehensive literature search of PubMed and the Cochrane Library was conducted to identify randomized controlled trials and systematic reviews examining the therapeutic potential of folinic acid in children with ASD. Ten studies published between 2016 and 2025 were included in this review. Collective findings demonstrated that folinic acid is associated with improvements in verbal communication, including receptive and expressive language in children with ASD. Notably, children who tested positive for FRAAs showed greater improvement. While these results are encouraging, barriers such as lack of FDA approval, insurance coverage denials, and provider hesitancy restrict the clinical use of folinic acid. Limitations such as small sample sizes, variability in dosing regimens, potential bias, and lack of long-term follow-up, demonstrate the need for further research. Larger, multicenter trials of longer duration are needed to validate these findings, support the development of standardized treatment protocols, and improve understanding of long-term efficacy and potential adverse effects. This review acknowledges the contributory role of abnormal folate metabolism in the pathophysiology of communication deficits in children with ASD. It further highlights folinic acid supplementation as a promising therapeutic strategy to enhance clinical outcomes in affected children.