Can diet affect thyroid function test results?

Yes, certain dietary factors can influence thyroid function test results. For instance, a diet high in iodine can affect T3 and T4 levels, potentially leading to hyperthyroidism or hypothyroidism. Additionally, deficiencies in selenium or iron can impair thyroid function. Foods rich in goitrogens (such as cruciferous vegetables like broccoli and cabbage) can interfere with thyroid hormone production when consumed in large amounts. If you are undergoing a thyroid function test, inform your doctor about any significant dietary changes, particularly if you are taking iodine supplements or following a strict diet that may impact thyroid health.