Urinary Iodine
The measurement of urinary iodine (UI) provides an accurate approximation of dietary iodine intake in view of the fact that the majority of iodine ingested (~90%) is excreted via the urine. Therefore, UI measurements provide a biological indicator of Iodine Deficiency Disorders.
Iodine's main action is involved in thyroid function. Due to the numerous actions carried out by the thyroid, the implications of iodine deficiency are vast. The major hormone secreted by the thyroid is thyroxine, also called T4 because it contains 4 iodine atoms. To exert its effects, T4 is converted to T3 by the removal of one iodine atom. This occurs mainly in the liver and other tissues where T3 acts, such as the brain. Other actions include the formation and integrity of normal breast tissue, foetal brain development and function, and anti-microbial effects.
