Iodine intake influences thyroid disease risk. Which statement is true?

• A. Iodine deficiency can cause goiter and hypothyroidism; excess can trigger autoimmune thyroid disease or hyperthyroidism; iodized salt and seafood are common sources; caution in autoimmunity and pregnancy
• B. Iodine deficiency causes hyperthyroidism
• C. Iodine has no effect on autoimmune thyroid disease
• D. Iodine is only important for pregnancy; not for other ages

Answer: (C)