Final answer:
The nurse should teach the patient about calcium supplements to normalize serum calcium levels.
Step-by-step explanation:
Hypoparathyroidism is a condition characterized by low levels of calcium in the blood. In this case, the patient developed hypoparathyroidism after having radical neck surgery to remove a malignant tumor. The nurse should plan to teach the patient about calcium supplements to normalize serum calcium levels. Calcium supplements can help raise the calcium levels in the blood, which is important for the functioning of nerves, muscles, and bones.