Iron Deficiency in Athletes — Current State of Knowledge

Abstract

Introduction and Purpose. Iron deficiency is common among athletes and may occur before anemia develops. Its significance is less clear when iron stores are depleted despite normal hemoglobin. This review summarizes current evidence on iron deficiency in athletes, with particular emphasis on iron deficiency without anemia (IDNA), athletic performance, diagnosis, and management.

Materials and Methods. A structured PubMed/MEDLINE search was supplemented by Google Scholar and reference screening. Publications from January 2015 to August 2026 were considered, with earlier studies included when relevant to fundamental aspects of iron metabolism, diagnosis, or treatment.

Results. Iron deficiency in athletes results from interacting factors, including increased requirements, inadequate intake, reduced iron availability, and iron losses. Ferritin remains the principal marker of iron stores, although inflammation and inconsistent diagnostic thresholds complicate its interpretation. The functional effects of IDNA are variable. More pronounced depletion appears more likely to impair endurance performance, while increases in ferritin after supplementation do not consistently translate into improved performance.

Conclusions. Iron status should be interpreted alongside laboratory findings, symptoms, risk factors, and training demands. Management should focus on correcting documented deficiency and identifying its underlying cause rather than supplementation aimed solely at increasing iron stores or enhancing performance.