The document summarizes iodine metabolism. It states that iodine is primarily stored in the thyroid gland where it is used to synthesize the thyroid hormones triiodothyronine and tetraiodothyronine. Dietary sources of iodine include seafood, eggs, dairy, and iodized salt. A deficiency of iodine can lead to goiter or cretinism in children, while excess iodine or goitrogenic substances can also interfere with thyroid hormone production.