Global prevalence of iron deficiency and iron-deficiency anemia among adolescents (ages 10–19 years): a systematic review and meta-analysis

Background Iron deficiency (ID) and iron-deficiency anemia (IDA) are the most prevalent nutritional disorders globally and the leading cause of disability-adjusted life-years lost in adolescents. Objectives To estimate the pooled global prevalence of ID and IDA in adolescents aged 10–19 years, characterize sex and geographic disparities, identify modifiable risk factors, and examine the evidence base relevant to routine complete blood count (CBC) and ferritin screening. Methods MEDLINE, Embase, Cochrane Library, and Web of Science were searched in across three periods (May 2023, January 2024, and April 2026); 321 studies from 45 countries were included in the systematic review. The subset reporting extractable, ferritin-based prevalence with a denominator contributed to the meta-analyses ( k = 30 studies for girls’ IDA; k = 65 for iron deficiency). Random-effects meta-analysis with the Freeman–Tukey double-arcsine transformation (DerSimonian-Laird) was applied; each pooled estimate is reported with a 95% prediction interval and leave-one-out sensitivity analyses. Evidence certainty was rated using GRADE. PROSPERO: CRD420261360798. Results Pooled IDA prevalence in adolescent girls was 20.0% (95% CI: 12.6%–28.7%; k = 30; I 2 = 96.3%; 95% prediction interval: 0%–74%), with similar rates in low- and middle-income countries (LMICs) (21.7%) but lower in high-income countries (10.7%). Boy-specific IDA could not be reliably pooled because no included study provided an extractable boys-only IDA denominator. Pooled ID (low ferritin, with or without anemia) was higher: 26.7% overall ( k = 65), 26.5% in girls and 13.9% in boys ( k = 4); the nationally representative Indian Comprehensive National Nutrition Survey (CNNS) showed a prevalence of 30.4% in girls vs. 11% in boys. In Israel, 13.2% of adolescents were anemic and 37.2% of female military recruits had low ferritin. Leave-one-out analysis confirmed the estimates were robust to removal of any single study. Heterogeneity was very high ( I 2 > 90%); pooled estimates are therefore interpreted together with their wide prediction intervals rather than as single underlying values. Key risk factors included female sex, menstrual blood loss, LMIC residence, and a plant-based diet. Conclusions IDA affects approximately one in five adolescent girls globally, with a comparable pooled prevalence in LMICs and a lower prevalence in high-income countries; ID with or without anemia is more common. These prevalence data identify a substantial disease burden and support consideration of CBC and serum ferritin screening in adolescents, together with iron supplementation in high-burden settings and targeted dietary interventions. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261360798 , identifier CRD420261360798.