Iron in Chronic Kidney Disease and End-Stage Kidney Disease-Current Trends and Future Direction.

Anaemia is a frequent and serious complication in chronic kidney disease (CKD), affecting both non-dialysis-dependent (NDD) and dialysis-dependent (DD) patients. While erythropoietin (EPO) deficiency is the primary cause, iron deficiency (ID) also plays a crucial role. ID in CKD can be classified as either absolute, resulting from blood loss, or functional, driven by inflammation and elevated hepcidin levels, which trap iron in macrophages and hepatocytes, preventing its use in erythropoiesis. Elevated hepcidin also reduces dietary iron absorption in the gut, making oral iron supplements ineffective, particularly in advanced CKD. This review summarises the available intravenous (IV) iron formulations, discusses diagnostic definitions and treatment thresholds for ID in NDD and DD CKD, and explores potential future therapeutic directions.