Pathophysiology
Depletion of storage iron (ferritin), then transport iron (transferrin saturation), then Hb synthesis; hepcidin regulation critical.
Sources: AGA IDA 2020 (Gastroenterology 2020;159:1085); BSH IDA (BJH 2013;161:639)
Presentation
Fatigue, dyspnoea, pallor, pica, koilonychia, restless legs; angular cheilitis. Menstrual loss in women, occult GI bleed in men and postmenopausal women.
Diagnosis
Low MCV, MCH, low ferritin (<30 ng/mL) with high total iron-binding capacity. In inflammation, ferritin may be normal - check transferrin saturation <20%.
Management
Identify and treat source (endoscopy for adults). Oral iron 60-120 mg elemental every other day (better absorption). IV iron (ferric carboxymaltose, ferric derisomaltose) for intolerance, malabsorption, CKD, IBD, or ongoing losses.
