Physiology A patient is on low calcium diet for 8 weeks. Level of which of the following increases to maintain serum calcium levels? A PTH B Calcitonin C Active 24, 25 dihydroxy cholecalciferol D Serum phosphate level 💡 Explanation A patient is on low calcium diet for 8 weeks. Level of which of the following increases to maintain serum calcium levels? ✓ Correct Answer: A. PTH