Why does hypothyroidism sometimes persist despite adequate iodine intake in a patient with a functional thyroid gland?

💡 Explanation

Hypothyroidism can occur despite sufficient iodine due to impaired conversion of T4 to T3 in peripheral tissues. Deiodinase enzymes are crucial for this conversion; therefore, if these enzymes are deficient or inhibited, T3 levels remain low, leading to hypothyroid symptoms, rather than iodine deficiency being the direct cause.

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