Iodine

Iodine is an essential trace element crucial for thyroid hormone synthesis. These hormones, thyroxine (T4) and triiodothyronine (T3), regulate metabolism, growth, and development across all stages of life. The body cannot produce iodine, so it must be obtained through diet. Common dietary sources include seafood, dairy products, and iodized salt. Urine iodine concentration reflects recent dietary intake and is the preferred method for assessing population-level iodine status. Individual urine iodine measurements can help evaluate nutritional sufficiency, especially in regions where dietary intake may vary.