This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Calcium Metabolism, Subject name: Physiology
[{'content': 'Which one of the following vitamins stimulates calcium absorption by the GI tract? \nSelect and explain. \nA. Vitamin E, B. Vitamin D, C. Vitamin A, D. Vitamin K', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Vitamin DVitamin D plays an important indirect role in the absorption of calcium by the GI tract. The other vitamins listed are not involved in the absorption of calcium.', 'role': 'assistant'}]