Most sensitive and specific test for diagnosis of iron deficiency is:: (A) Serum iron level, (B) Serum ferritin levels, (C) Serum transferrin receptor populations, (D) Transferrin saturation
Answer is B. b. Serum ferritin levels(Ref: Nelson's 20/e p 2323-2325, Ghai 8/e p 334-335)Low serum ferritin level invariably indicates iron deficiency and hence it is the most specific and sensitive test for iron deficiency anemia.