This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'A patient has Hb 6gm%, folic acid 8 ng/ml, vitamin B12 60pg/ml, serum iron 16011g/d1, and MCV-104. The diagnosis is: \nSelect and explain. \nA. Iron deficiency anemia, B. Vitamin B12 deficinecy, C. Folic acid deficiency, D. Pyridoxine deficiency', 'role': 'user'}, {'content': "Answer: B \nExplanation: Answer is B (vitamin Bp is Deficiency) Presence of anemia (Hb= 6gm%) Macrocytosis (MCV=104) and decreased vitamin B12 levels (B12=60 pg/ml) suggests a diagnosis of megaloblastic anemia due to vitamin B12 deficiency. Reference values from Harrison's Appendix A Parameter Normal Values Patient value Inference Hb 13-18 g/dl 6 gmldl Anemia HCV 79-93.3/L 104 fL Macrocytosis Vitamin B12 >250 pg/ml 60 pg/mI Vitamin B12 deficiency Folic Acid 5.4-18.0 ng/ml 8 ng/ml Normal folate levels Iron 30-160 ug/dl 160 ug/dl Normal The patient in question, thus has a macrocytic anemia due to vitamin B12 deficiency.", 'role': 'assistant'}]