A public-health authority considers adding iodine to a national salt supply to reduce endemic goiter. Which evaluation best balances benefits and potential risks?

• A. Universal salt iodization is generally beneficial in areas with iodine deficiency to prevent goiter and cognitive deficits, but the program should be monitored for excessive intake in individuals and adjusted as population iodine status improves to avoid iodine-induced thyroid dysfunction in sensitive people.
• B. Iodine should only be supplied through high-dose supplements to select individuals since adding to salt will not change population iodine status; therefore no monitoring is necessary.
• C. The only acceptable public-health action is to mandate large-scale vitamin A fortification of salt instead of iodine because vitamin A and iodine have identical effects on thyroid and cognitive development, and vitamin A carries no risk of excess.
• D. Iodizing the entire salt supply is always harmful because any additional micronutrient in a broad population will inevitably cause toxicity and should be avoided regardless of endemic deficiency.

Answer: (A)