The purpose of the study was to establish the vitamin-mineral status of children with autism spectrum disorders (ASD) who exhibit attention-deficit/hyperactivity disorder (ADHD). Four research questions were formulated for the study. A quasi-experimental of ex post facto research design was used. The study was conducted in four special schools and clinical centers in Jos Township, Nigeria. The study population were children with autism spectrum disorders, who were diagnosed with the ADHD characteristics of poor attention (short attention span), hyperactivity (out-of-seat), and impulsivity. The results of the study revealed a missing or reduced vitamin-mineral status of the participating children in most of the vitamin-mineral elements tested. There was also a reduction in the exhibition of ADHD in the experimental group as a result of vitamin-mineral supplementation. The study concluded that vitamin-mineral elements deficiency in children with ASD resulted in their ADHD and recommended regular testing of children to ensure their vitamin-mineral levels are in balance.