<prompt> Best marker of iron deficiency anemia is?Serum ironSerum ferritinTotal iron binding capacityTransferrin saturation  <response>: ANSWER: B Serum ferritinREF: Harrisons 18th ed ch: 103Serum ferritin is the most specific and sensitive test for iron deficiencyUnder steady-state conditions, the serum ferritin level correlates with total body iron stores; thus, the serum ferritinlevel is the most convenient laboratory test to estimate iron stores. 