Effect of zinc supplementation in zinc-deficient children with attention-deficit hyperactivity disorder

Abstract

Background Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder increasing in prevalence. Although there is limited evidence to support treating ADHD with mineral supplements, research does exist showing that patients with ADHD may have reduced levels of zinc, ferritin, and magnesium. These nutrients have important roles in neurologic function, including involvement in neurotransmitter synthesis. In spite of the good response of many patients with ADHD to stimulant drugs, a substantial percent do not respond to or develop significant side effects from stimulants. For this reason, zinc treatment has been considered to show positive results on various symptoms in ADHD patients with zinc deficiency. Objectives The aim of this study is to elucidate the effect of zinc supplementation on ADHD symptoms in zinc-deficient ADHD children. Patients and methods Thirty zinc-deficient children diagnosed with ADHD and on a fixed dose of methylphenidate were enrolled in this study. They were assigned to zinc supplementation (30 mg/day) as gluconate in an open-label follow-up trial for 10 weeks. Results There was a statistically significant difference among zinc-deficient ADHD children before and after zinc supplementation on all working memory index subtest scores and all Conner’s subscale scores. This result points to the effect of zinc supplementation on ADHD symptom domains.