Iron deficiency linked to higher odds of ADHD in children

Children with attention-deficit/hyperactivity disorder had lower serum ferritin levels and a higher prevalence of iron deficiency than healthy controls in a retrospective case-control study that accounted for inflammation. The study included 156 children aged 6–12 years with DSM-5-defined ADHD and 164 healthy controls identified from hospital records. Median serum ferritin was 24.6 µg/L in the ADHD group, compared with 35.8 µg/L in controls, a statistically significant difference (P < 0.001).

Iron deficiency, defined by the researchers as serum ferritin below 30 µg/L, was identified in 42.3% of children with ADHD and 18.9% of controls (P < 0.001). The investigators extracted iron indices, hematologic parameters and C-reactive protein (CRP) from the records. They used logistic regression, restricted cubic splines and a population attributable risk fraction to assess the relationship between ferritin and ADHD while accounting for inflammatory status and other measured variables.

The association remained after the researchers adjusted for age, sex, body mass index, CRP, parental education, family history of ADHD, picky eating and meat intake. In that fully adjusted model, iron deficiency was associated with 2.45 times the odds of ADHD, with a 95% confidence interval of 1.58–3.80. Restricted cubic spline analysis indicated increased odds of ADHD at serum ferritin concentrations below 30 µg/L. The fully adjusted model-based population attributable risk fraction for iron deficiency was 19.7%.

The researchers also performed a sensitivity analysis excluding children whose CRP concentration was 10 mg/L or higher. Iron deficiency remained associated with ADHD in this subgroup, with an adjusted odds ratio of 2.78 and a 95% confidence interval of 1.74–4.44. This result shows that the overall association was not confined to children with the higher inflammatory marker values excluded by the analysis.

Despite the adjusted associations, the study cannot determine whether iron deficiency preceded ADHD or resulted from ADHD-related dietary behavior. Its retrospective case-control design compared children already identified with ADHD against healthy controls rather than following children over time. The authors said ferritin interpreted alongside CRP may help characterize iron status in children evaluated for ADHD, but prospective longitudinal and interventional studies are needed to clarify directionality and clinical relevance. The article was published online in BMC Pediatrics on 31 August 2026 as an open-access, peer-reviewed accepted manuscript and is subject to further edits before replacement by the final version of record.

Subject of Research: Association between serum ferritin, iron deficiency, inflammation and ADHD in children aged 6–12 years

Article Title: Serum ferritin and ADHD in children: a case-control study accounting for inflammation

Article References: Jin, J., Xu, Y., Su, Q., Sheng, J., Yin, Y., & He, B. (2026). Serum ferritin and ADHD in children: a case-control study accounting for inflammation. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07528-5

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07528-5

Keywords: ADHD, children, iron deficiency, serum ferritin, inflammation, C-reactive protein, case-control study, hematology, odds ratio, child health, Serum, ferritin