Although iron deficiency is well documented, less is known about dietary involvement in symptomatic iron deficiency manifesting in medical conditions. In this study, we quantified the global burden of dietary iron deficiency, focusing on where inadequate dietary iron intake leads to clinical manifestations such as anemia. We analyzed data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 to estimate dietary iron deficiency prevalence and disability-adjusted life years (DALYs), stratified by age, sex, geography and socio-demographic index (SDI) across 204 countries. In 2021, global age-standardized prevalence and DALY rates were 16,434.4 (95% uncertainty interval (UI), 16,186.2–16,689.0) and 423.7 (285.3–610.8) per 100,000 population, with rates decreasing by 9.8% (8.1–11.3) and 18.2% (15.4–21.1) from 1990 to 2021. A higher burden was observed in female individual (age-standardized prevalence, 21,334.8 (95% UI, 20,984.8–21,697.4); DALYs, 598.0 (402.6–854.4)) than in male individual ((age-standardized prevalence, 11,684.7 (11,374.6–12,008.8); DALYs, 253.0 (167.3–371.0)). High-SDI countries presented greater improvement, with a 25.7% reduction compared to 11.5% in low-SDI countries. Despite global improvements, dietary iron deficiency remains a major health concern with a global prevalence of 16.7%, particularly affecting female individuals, children and residents in low-SDI countries. Urgent interventions through supplementation, food security measures and fortification initiatives are essential.