Final answer:
In the GI tract, iodine from foods is converted into thyroid hormones. The thyroid gland absorbs most of the iodine.
Step-by-step explanation:
In the GI tract, iodine from foods is converted into thyroid hormones. The thyroid gland uses iodine in the process of its normal function, and any iodide that enters the bloodstream is usually removed by and concentrated in the thyroid gland. The thyroid gland absorbs most of the iodine, allowing it to be imaged for diagnostic purposes or preferentially irradiated for treatment purposes.