This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
[{'content': 'Dose of vitamin A during pregnancy - \nSelect and explain. \nA. 600 mg, B. 800 mg, C. 950 mg, D. 350 mg', 'role': 'user'}, {'content': "Answer: B \nExplanation: During pregnancy recommended allowance of vitamin A is 800mcg . REF. PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICAL 21ST EDITION. PAGE NO - 616", 'role': 'assistant'}]