This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of Bone & Fracture Healing, Subject name: Orthopaedics
Increased alkaline phosphatase is seen in - 
Select and explain. 
A. Osteoporosis, B. Multiple myeloma, C. Paget's disease, D. Osteolytic metastasis
C: Paget's disease
Answer: C: Paget's disease 
Explanation: Ans. is 'c' i.e., Paget's disease o Whenever the activity of osteoblasts increase, serum alkaline phosphatase is raised. Therefore, serum alkaline phosphatase acts as an index of osteoblastic activity.o The conditions in which osteoblastic activity is increased and hence the alkaline phosphatase in increased are : -i) Rickets/osteomalaciav) Paget's disease (osteitis deformans)ii) Primary hyperparathyroidismvi) Osteoblastic secondariesiii) Renal osteodystrophy (secondary hyperparathyroidism) iv) Chronic renal failure and secondary hyperparathyroidism