Iron repletion

Class

Intravenous/oral iron replacement therapy

Iron is an essential cofactor for hemoglobin, the oxygen-carrying protein in red blood cells, and for numerous enzymes involved in cellular energy metabolism. When iron stores are insufficient—due to chronic blood loss, poor dietary absorption, or increased demand—red blood cell production falters, producing iron-deficiency anemia along with fatigue, reduced exercise tolerance, and impaired organ function. Iron repletion therapy aims to restore body iron stores and support normal erythropoiesis (red blood cell formation). While mild deficiency can often be corrected with oral iron salts, oral absorption is limited and frequently poor in conditions such as inflammatory bowel disease, chronic kidney disease, or heart failure, where gut absorption is impaired or ongoing losses exceed what oral dosing can replace. Intravenous iron complexes address this by delivering iron directly into the circulation, bypassing the gut entirely. These formulations bind iron within a carbohydrate shell that controls its release, allowing larger doses to be given safely and more rapidly than oral iron would permit. This mechanism matters broadly across nephrology, cardiology, gastroenterology, and oncology, wherever chronic disease or blood loss produces iron-restricted anemia that oral therapy cannot adequately correct.