Effect of Vitamin D Supplementation on Inflammatory Biomarkers in School-Aged Children with Attention Deficit Hyperactivity Disorder

Abstract

Background and Objective. Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent psychiatric and developmental disorders in children. Low serum vitamin D concentration and elevated inflammation biomarkers might be involved in neuropsychiatric disorders, such as ADHD. The purpose of this study was to evaluate the effect of vitamin D supplementation on TNF-α and IL-6 levels in children with attention deficit hyperactivity disorder. Method. This randomized double-blind, placebo-controlled trial was conducted on 75 school-aged children with a diagnosis of ADHD based on DSM-V criteria. Children were randomly allocated to receive either vitamin D3 (2000 IU/day) or a placebo for 3 months. Serum IL-6, TNF-α, and 25(OH) D were assessed before and after the intervention to determine the effects of vitamin D on the highlighted parameters. Results. Serum levels of 25(OH) D increased significantly in the vitamin D group ( $P=0.01$ ). However, no significant differences in serum IL-6 and TNF-α were found between both groups at the baseline and at the end of the intervention. Conclusion. The findings revealed that vitamin D supplementation for 3 months is not efficacious in reducing inflammatory cytokines in children with ADHD. Further studies are required to confirm these results.