Toxic Factors Affecting ‘Iodine Sufficiency’
Specific tissues in the body require adequate iodine and the reduced form of the element, iodide for normal metabolism and optimal health. Adequate iodide uptake and organification of iodine by the thyroid gland is required for the production, storage and release of thyroid hormones. Triiodothyronine (T3) regulates metabolism in several tissues by affecting energy production and neuronal and sexual development. Iodine insufficiency is associated with “sub-clinical” thyroid deficiency, weight gain, loss of energy, goiter and impaired mental function. Iodine is also concentrated in breast tissue where it elicits anti-proliferative effects and protection against fibrocystic breast disease and cancer. Iodine and organic iodine compounds are also concentrated and secreted by the gastric mucosa, salivary glands and the cervix.
Iodine status and it’s metabolism is affected not only by iodine intake, which has decreased in Australia significantly, but also by intake and retention of the goitrogenic halides (bromide and fluoride). Iodide uptake by specific cells is mediated by an energy-dependent sodium/iodide symporter (NIS). Bromide and fluoride are non-essential, toxic halides that avidly compete with iodide for the NIS. Excessive intake of the antagonistic halides can therefore accumulate in tissues, displace iodine and compromise the production of thyroid hormones and the integrity of the thyroid and mammary glands. Antagonistic bromide is abundant in commercially produced baked goods, soft drinks, pesticides, brominated chemicals and some medications. Primary sources of fluoride include fluoridated water, beverages, toothpaste, mouthwashes and some medications.
Achieving comprehensive Iodine Assessment (with Halides)
The Urine Halides test provides comprehensive assessment of iodine sufficiency and the burden of antagonistic halides in a single test. The test requires a spot urine specimen (first morning void preferred) for determination of baseline halide levels. In order to calculate a retention vs excretion rate (assessing iodine sufficiency), Doctor’s Data suggests an oral loading dose of iodine/iodide be ingested and all urine collected for the subsequent 24 hours. Low iodine excretion is then suggestive of a greater bodily need. Iodine and any displaced bromide and fluoride are measured in the urine and the results for each element are reported as ug/gm creatinine and ug/24 hours.
These highly elusive halides are each analysed in urine via analysed in urine using the most accurate methodology available for that element. Iodine and bromine are measured by ICP-MS under conditions that convert all iodide and bromide to their respective free halogens (oxidised). Urinary fluoride is most accurately measured using an ion specific electrode.
This test provides an added assessment of the remaining ‘toxic’ halogens that obstruct Iodine utilisation and therefore provides the most comprehensive assessment of Iodine status (including its availability) in the body.
This test is ideal for any first time assessments, situations of autoimmunity, thyroid pathology, and suspected toxicity.
Note: See Urine Iodide – Pre and Post Loading test for a more in-depth review of how 24-hour pre and post iodine load urine testing offers the best determination of body Iodine status.