Iodine Loading Test | Vitamin Research

The gold standard test for iodine sufficiency is called the iodine loading test. The iodine/iodide loading test is based on the concept that the human body has a mechanism to retain ingested iodine until whole body sufficiency for iodine is achieved. During optimal iodine supplementation, a mechanism is triggered that progressively adjusts the excretion of iodine to balance the intake. As the body iodine content increases, the percent of the iodine load retained decreases with an increase in the amount of iodide excreted in the 24 hr urine collection. The more deficient a subject is in iodine, the more iodine is retained by the body and the least excreted in the urine. Sufficiency is achieved when 90% or more of the ingested amount is excreted in the urine. The test consists of ingesting a high dose iodine/iodide (50 mg). Urinary iodide levels are measured in the following 24 hr collection