Final answer:
The best response for the nurse when instructing the client about the use of supplemental iodine is to take the iodine supplement with food, as it enhances absorption and effectiveness.
Step-by-step explanation:
The best response for the nurse when instructing the client about the use of supplemental iodine would be to take the iodine supplement with food. Absorption of iodine and iodide occurs most readily in the small intestine. Taking the supplement with food can help enhance absorption and improve its effectiveness. Additionally, it is important to note that in the United States where dietary iodine is almost always adequate, iodine deficiency is unlikely to be the cause of hypothyroidism, therefore taking supplemental iodine is not likely to correct the problem.