Therapeutic Effects of Dietary Supplements on Emotion-Related Symptoms in Children and Adolescents with Autism: A Systematic Review and Meta-analysis.

BACKGROUND

Autism spectrum disorder (ASD) is frequently accompanied by emotional symptoms such as irritability and anxiety, which significantly impact quality of life. Dietary supplements have been proposed as potential interventions, but their efficacy for emotion-related symptoms in children and adolescents with ASD remains unclear.

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the efficacy of various dietary supplements in improving emotion-related symptoms in children and adolescents with ASD, and to explore differences across supplement types.

METHODS

PubMed, Cochrane Library, Web of Science, and Embase were searched from inception to 15 May, 2025. Randomized controlled trials (RCTs) evaluating dietary supplements for emotion-related symptoms in children and adolescents with ASD were included. Primary outcomes were irritability, anxiety, and overall emotional symptoms. Data were pooled using random-effects models to calculate standardized mean differences (SMD) with 95% confidence intervals (CIs). Subgroup analyses were conducted by supplement type and emotion category. Study quality was assessed using the Cochrane risk of bias (RoB) 2.0.

RESULTS

Twenty-one RCTs (22 studies) comprising 866 participants were included. Dietary supplements significantly improved irritability (SMD = -0.36, 95% CI: -0.68, -0.05, P = 0.02) and overall emotional symptoms (SMD = -0.44, 95% CI: -0.81, -0.08, P = 0.02) compared with control groups, with small-to-moderate effect sizes. No significant improvement was observed for anxiety (SMD = -0.15, 95% CI: -0.45, 0.14, P = 0.32). Subgroup analyses by supplement type showed that vitamin supplements had some benefits for irritability (SMD = -0.44, 95% CI: -0.79, -0.10, P = 0.01). Other supplement types showed nonsignificant effects. Moderate-to-high heterogeneity was observed across analyses (I2 = 64.42%-68.41%). Sensitivity analyses excluding high-risk bias studies confirmed the robustness of findings.

CONCLUSIONS

Dietary supplements may improve irritability and overall emotional symptoms in children and adolescents with ASD. However, evidence strength is limited by study heterogeneity, RoB, and small-sample sizes. High-quality, large-scale RCTs are needed to confirm these findings and establish optimal intervention protocols.