Which population is most at risk for severe outcomes from iodine deficiency?

• A. People who drink fluoridated water, since fluoride completely blocks iodide transport into the thyroid in everyone.
• B. Individuals who exclusively consume iodized salt, as they always develop goiter due to excess iodine deposits.
• C. Healthy young adults who eat a varied diet, because they are least able to store iodine and suffer immediate neurologic decline.
• D. Fetuses and infants (due to risk of congenital hypothyroidism causing stunted growth and impaired brain development).

Answer: (D)