Iron deficiency

State of diminished total body iron stores, with reduced ferritin and transferrin saturation, leading to impaired erythropoiesis (anemia) and other iron-dependent functions. Possible causes are blood loss (menstruation, GI bleeding, asprin, NSAIDs, frequent blood donation), malabsorption (celiac disease, gastric bypass), inadequate dietary intake (vegan/vegetarian), and increased need (pregnancy, growth spurts).