This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Physiology
[{'content': 'Increased calcium levels lead to \nSelect and explain. \nA. Increased 1,25 dihydroxycholecalciferol, B. Increased 24,25 dihydroxycholecalciferol, C. Decreased calcitonin, D. Increased parathormone', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 24,25-dihydroxycholecalciferol; a metabolite in calcium metabolism, formed in the kidney from 25-hydroxycholecalciferol by the activation of a 24-hydroxylase.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-379', 'role': 'assistant'}]