Role of Micronutrients in the Management of Autism Spectrum Disorders: A Systematic Review and Meta-Analysis

Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders characterized by increased developmental, educational, and social demands. Recent evidence suggests that up to 40%-50% of symptom variability may be determined by environmental factors including nutritional deficiency of folate, omega-3 fatty acids, and Vitamin D. Studies exist which advocate the use of micronutrient therapy to improve brain function. However, there is no consensus on their use in ASD and opinions remain divisive. This study aims to identify the role of micronutrients in ASD. We searched PubMed, Google Scholar, and Cochrane Library from the period of January 2010 to January 2022. We excluded animal studies, cross-sectional studies, and less 10 participants in a study. An initial literature search yielded a total of 666 studies, out of which 26 studies were included in the systematic review with a pooled sample of 12086 patients. Twelve studies showed an improvement in the symptoms of ASD patients when they were treated with micronutrients and seven studies found an association between micronutrient levels and ASD symptoms. The results of the meta-analysis in seven studies show that micronutrient therapy has a beneficial effect in reducing the severity of ASD, albeit being statistically insignificant (log odds ratio = -1.03, 95% confidence interval: -2.11-0.05). Our study suggests that in spite of low quality of evidence and randomized data, universal micronutrient supplementation may be started in children diagnosed with ASD due to the potential of reducing the severity of ASD along with a low risk of side effects.