This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Anatomy
[{'content': 'Which of the following are features of iron deficiency anemia except \nSelect and explain. \nA. Increased RDW, B. Decreased serum iron, C. Decreased TIBC, D. Decreased serum ferritin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ref Harrison 19 th ed pg 627 The serum iron level repre- sents the amount of circulating iron bound to transferrin. The TIBC is an indirect measure of the circulating transferrin. The normal range for the serum iron is 50-150 mg/dL; the normal range for TIBC is 300-360 mg/dL. Transferrin saturation, which is normally 25-50%, is obtained by the following formula: serum iron x 100 / TIBC. Iron- deficiency states are associated with saturation levels below 20%. There is a diurnal variation in the serum iron.', 'role': 'assistant'}]