Can a thyroid function test diagnose iodine deficiency?

A thyroid function test (TFT) can help detect the effects of iodine deficiency, which is a common cause of hypothyroidism. Iodine is essential for the production of T3 and T4 hormones, and a deficiency may lead to low T4 and high TSH levels. However, the test itself doesn’t directly measure iodine levels. If iodine deficiency is suspected, your healthcare provider may recommend additional tests, such as a urinary iodine concentration test, to confirm the diagnosis. Correcting iodine deficiency through diet or supplements can help restore normal thyroid function.