A new meta-analysis published in 2025 has explored the potential impact of B and D vitamins on people with attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). This study reviewed 12 studies involving 652 individuals with ASD and 10 studies involving 852 individuals with ADHD, with or without hyperactivity. In total, 787 participants received vitamin supplements, while 717 were in control groups that did not receive the supplements. The findings aim to clarify whether these vitamins could offer any therapeutic benefit for individuals with these conditions. ASD is a neurodevelopmental condition marked by challenges in social interactions and communication, along with repetitive behaviors and narrow interests. ADHD, on the other hand, is characterized by difficulty focusing, impulsivity, and, in some cases, hyperactivity. Both conditions can significantly impact daily life, prompting research into various treatment options, including nutritional interventions. For individuals with ASD, the study found that B vitamins—particularly B6, B9, and B12—seemed to have a noticeable effect. Researchers observed improvements in emotional regulation and a reduction in repetitive or stereotypical behaviors. The effect size, a measure of the magnitude of the impact, was 0.42, which suggests a moderate benefit. However, the results for ADHD were different. In this group, vitamin D was linked to a decrease in certain behavioral issues and an improvement in attention in children who were followed over time. While the findings suggest that vitamin supplements may offer some benefit for individuals with ASD and ADHD, the researchers emphasize that more studies are needed to confirm these results. The study does not suggest that vitamins should replace traditional treatments but highlights the potential for nutritional support as part of a broader approach to managing these conditions.