Iron Deficiency Without Anemia: Recognition, Causes, and Clinical Management
DOI:
https://doi.org/10.12775/JEHS.2026.95.73645Keywords
iron deficiency, ferritin, hepcidin, non-anaemic deficiency, fatigue, cognitive function, performance, chronic inflammation, micronutrient status, preventive medicineAbstract
Iron deficiency without anemia (IDWA) represents a hidden yet prevalent condition that disrupts fundamental physiological processes long before classical pre-anemia becomes apparent. Although hemoglobin concentration remains within reference limits, depleted iron stores impair energy metabolism, cognitive capacity, and physical endurance (Camaschella, 2019). Across diverse populations—women of reproductive age, children, older adults, and athletes—this latent deficiency compromises health, productivity, and quality of life (Lopez et al., 2016). Modern diagnostic tools now make early detection possible through measurement of ferritin, transferrin saturation, and inflammatory indicators such as hepcidin (Pasricha et al., 2021). Still, awareness among clinicians and the general public remains limited. This review integrates contemporary evidence concerning iron metabolism, mechanisms of deficiency, epidemiology, clinical presentation, and management strategies, highlighting the importance of early recognition. By synthesising insights from haematology, nutrition science, and performance physiology, the paper aims to provide a comprehensive foundation for improved prevention and treatment of this under-recognised disorder.
References
Arosio, P., Elia, L. & Poli, M. (2021) 'Ferritin, cellular iron storage and regulation,' Blood Reviews, 46, p. 100733.
Beard, J.L. (2003) 'Iron deficiency alters brain development and functioning,' Journal of Nutrition, 133(5 Suppl 1), pp. 1468S–1472S.
Burden, R.J. et al. (2016) 'Iron deficiency in athletes: a contemporary review,' European Journal of Applied Physiology, 116, pp. 1845–1855.
Camaschella, C. (2015) 'Iron-deficiency anemia,' New England Journal of Medicine, 372(19), pp. 1832–1843.
Camaschella, C. (2019) 'Iron deficiency,' Blood, 133(1), pp. 30–39.
De Bortoli, N. et al. (2018) 'Iron deficiency as the presenting feature of celiac disease,' Gastroenterology Research and Practice, 2018, pp. 1–7.
DellaValle, D.M. & Haas, J.D. (2019) 'Mitochondrial dysfunction in iron-deficient muscle,' Medicine & Science in Sports and Exercise, 51(4), pp. 781–789.
Drakesmith, H. & Prentice, A.M. (2012) 'Hepcidin and the iron-infection axis,' Science, 338, pp. 768–772.
Ganz, T. & Nemeth, E. (2015) 'Iron homeostasis in host defence and inflammation,' Nature Reviews Immunology, 15, pp. 500–510.
Hentze, M.W. et al. (2010) 'Two to tango: regulation of mammalian iron metabolism,' Cell, 142(1), pp. 24–38.
Hurrell, R.F. & Egli, I. (2010) 'Iron bioavailability and dietary reference values,' American Journal of Clinical Nutrition, 91(5), pp. 1461S–1467S.
Jimenez, K., Kulnigg-Dabsch, S. & Gasche, C. (2015) 'Management of iron deficiency anemia,' Gastroenterology & Hepatology, 11(4), pp. 241–250.
Lopez, A. et al. (2016) 'Iron deficiency anaemia,' The Lancet, 387(10021), pp. 907–916.
Milman, N. (2022) 'Iron requirements in pregnancy,' Annals of Hematology, 101(1), pp. 7–15.
Munoz, M. et al. (2019) 'Iron deficiency and anemia in bariatric surgery patients,' Obesity Surgery, 29(10), pp. 3222–3232.
Murray-Kolb, L.E. & Beard, J.L. (2007) 'Iron treatment normalizes cognitive functioning in young women,' American Journal of Clinical Nutrition, 85(3), pp. 778–787.
Pasricha, S.-R. et al. (2021) 'Iron deficiency,' The Lancet, 397(10270), pp. 233–248.
Peeling, P. et al. (2017) 'Iron deficiency and fatigue: implications for athletic populations,' Sports Medicine, 47(1), pp. 93–104.
Peeling, P. & Hall, R. (2023) 'Iron deficiency in sport: balancing health and performance,' British Journal of Sports Medicine, 57(2), pp. 112–120.
Schrier, S.L. & Auerbach, M. (2023) 'Causes and diagnosis of iron deficiency and iron deficiency anemia in adults,' UpToDate [online]. Available at: https://www.uptodate.com (accessed March 2024).
Stoffel, N.U. et al. (2017) 'Iron absorption from oral iron supplements given on consecutive versus alternate days and as single morning doses versus twice-daily split dosing in iron-depleted women: two open-label, randomised controlled trials,' The Lancet Haematology, 4(11), pp. e524–e533.
Tolkien, Z., Stecher, L. & Kumar, A.V. (2015) 'Ferrous sulfate supplementation causes significant gastrointestinal side-effects in adults: a systematic review and meta-analysis,' PLOS ONE, 10(2), p. e0117383.
Wessling-Resnick, M. (2020) 'Inflammation and iron disorders,' Annual Review of Nutrition, 40, pp. 77–97.
Whitfield, K.C. et al. (2020) 'Global prevalence of inadequate iron intake,' Nutrients, 12(7), p. 2100.
Winkelman, J.W. (2021) 'Restless legs syndrome and iron deficiency,' Sleep Medicine Clinics, 16(3), pp. 373–384.
World Health Organization (2020) Micronutrient Deficiencies: Iron Deficiency Anaemia – Global Estimates. Geneva: WHO.
Yoo, K.H. et al. (2020) 'Serum ferritin and fatigue: a population study,' Journal of Psychosomatic Research, 132, p. 110117.
Zacharski, L.R. et al. (2020) 'Inflammation-induced functional iron deficiency,' Clinical Medicine, 20(4), pp. e460–e466.
Zimmermann, M.B. & Hurrell, R.F. (2007) 'Nutritional iron deficiency,' The Lancet, 370(9586), pp. 511–520.
Zittel, T.T. et al. (2020) 'Ferric carboxymaltose for the treatment of iron deficiency without anaemia: a systematic review,' British Journal of Haematology, 188(6), pp. 840–852.
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