This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Small Intestine Malabsorption disorders, Subject name: Pathology
[{'content': 'Which one of the following is not a cause of vitamin B12 deficiency? \nSelect and explain. \nA. Blind-loop syndrome., B. Dietary deficiency., C. Intrinsic factor deficiency., D. Resection of ascending colon.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: - Vit B12 is absorbed from ileum; hence resection of ascending colon has nothing to do with Vit B12 deficiency - Vit B12 deficiency is caused d/t: | Intake | Absorption - d/t decreased intrinsic factor, pancreatic & ileal diseases, fish tape worm infection | Requirement - as in children, pregnancy, lactation, blind loop syndrome', 'role': 'assistant'}]