healthunlocked.com/thyroidu... ~ discussing " Selenium, Iodine and Iron–Essential Trace Elements for Thyroid Hormone Synthesis and Metabolism" by Josef Köhrle Berlin, Germany.
msdmanuals.com/en-gb/profes... /professional/endocrine-and-metabolic-disorders/thyroid-disorders/hyperthyroidism "Iodine in pharmacologic doses inhibits the release of T3 and T4 within hours and inhibits the organification of iodine, a transitory effect lasting from a few days to a week, after which inhibition usually ceases. Iodine is used for emergency management of thyroid storm, for hyperthyroid patients undergoing emergency nonthyroid surgery, and (because it also decreases the vascularity of the thyroid) for preoperative preparation of hyperthyroid patients undergoing thyroidectomy. Iodine generally is not used for routine treatment of hyperthyroidism. The usual dosage is 2 to 3 drops (100 to 150 mg) of a saturated potassium iodide solution orally 3 times a day or 4 times a day or sodium iodide in 1 L 0.9% saline solution 0.5 to 1 g IV given slowly once a day."
"Excessive Iodine Promotes Pyroptosis of Thyroid Follicular Epithelial Cells in Hashimoto's Thyroiditis Through the ROS-NF-κB-NLRP3 Pathway" ~ study which links Hashimotos with too much iodine “in vitro”
sciencedirect.com/science/a... .... Matthew Kim, Paul Ladenson, in Goldman's Cecil Medicine (Twenty Fourth Edition), 2012
"THYROID.
Thyroid Hormone Transport and Metabolism
"More than 80% of the T3 present in target tissues is derived from T4 through the action of deiodinase enzymes that convert T4 to both T3, which contributes to the pool of T3 in the circulation, and biologically inactive reverse T3. The activity of deiodinase may be inhibited by systemic illness; iodide-containing compounds, including amiodarone and radiocontrast agents; glucocorticoid therapy; and selenium deficiency. Type 2 deiodinase is present in the pituitary gland and brain. Type 3 deiodinase is present in the glial cells of the central nervous system. It deactivates thyroid hormone by inner ring monodeiodination, a process that converts T4 to inactive reverse T3 (rT3) and T3 to inactive diiodothyronine (T2). Type 3 deiodinase is also expressed in placenta, accounting for the increased thyroxine dose requirement in pregnant women."
If you are referring to the reference I made to Japanese intake of iodine Tatty, I read that on Dr Myhill's website somewhere but unfortunately I haven't been able to locate it again although it did stick in my pile of sawdust at the time as both goitres and bc interested me greatly. Perhaps you may have better luck in finding it as you have a pile of straw which must be superior to sawdust😁
There are several different kinds of iodine supplement. Some forms of iodine are disinfectants rather than supplements. Wikipedia has a long list of possible formulations.
There is a relationship between selenium and iodine. People struggling to tolerate any iodine at all may be low in selenium. SeasideSusie recommended this selenium supplement :
This paper has a section on "Amiodarone and Hypothyroidism". It's worth reading the whole section (copied below) if you're worried about iodine (my bolding) :
"Amiodarone is an iodine-rich benzofuranic compound that is used to manage cardiac arrhythmias.13 It contains about 37% iodine by weight,14 and a 200-mg dose exposes the patient to about 300 times the recommended daily allowance.15,16 Due to its lipophilic nature, it concentrates in several tissues and organs, including the thyroid gland. Its active dealkylated metabolite, desethylamiodarone, tends to have a half-life of about 57 days, thus effects can be long-lasting even after discontinuation.16 Amiodarone-induced thyroid dysfunction could be secondary to iodine load or intrinsic effects of amiodarone itself. The iodine load from amiodarone can result in amiodarone-induced hypothyroidism (AIH) by inhibiting the oxidation of iodine, known as the Wolff-Chaikoff effect.17 This is particularly the case in patients with underlying or preexisting thyroid disease such as goiter or autoimmune thyroid disease.
Amiodarone by itself can also affect deiodinase activity.In vivo, it inhibits deiodinase-1 activity and pituitary deiodinase-2 activity, resulting in high T4, high reverse T3, and low T3. This may spur an initial increase in TSH that often returns to baseline in 2 to 3 months. With long-term treatment, TSH usually normalizes with total and free T4 and reverse T3 levels that remain slightly elevated. Early AIH may be present in 10% to 20% of patients treated with amiodarone, whereas the incidence with long-term treatment is often lower, from 5% to 10%. AIH is noted to be more frequent in iodine-sufficient areas of the world,18 and the presence of thyroid autoantibodies is associated with an increased likelihood of developing AIH. There is also an understanding that amiodarone may hasten the pathogenesis of Hashimoto thyroiditis. Since AIH manifests as primary hypothyroidism, diagnosis is similar to primary hypothyroidism, as is treatment with levothyroxine replacement (Figure 2).16
I just wanted to point out that I kept reading "AIH" as "Autoimmune Hypothyroidism" - but it isn't - in this paper it is "Amiodarone-Induced Hypothyroidism"
The reference to the Wolff-Chaikoff effect drew me to this article on wikipedia.
My personal opinion is that I would want a different treatment than Amiodarone for cardiac arrhythmia, if one exists, rather than risk my hypothyroidism getting worse. There are other alternatives, according to this link in the British National Formulary (BNF), but I haven't investigated them.
There is another possible result of taking high doses of iodine, caused by something known as the Jod-Basedow phenomenon - iodine-induced hyperthyroidism.
So, when it comes to iodine it seems we toss a coin as to whether we become hyperthyroid or hypothyroid. I haven't done enough reading to work out if one can foretell the result of iodine intake on an individual.
I don't think there is much controversy about inadequate iodine intake being an issue.
Plenty of questioning about exactly how much we need, how to test, how we manage iodine intake when taking thyroid hormones, etc. But the basic principle is fairly clear.
When it comes to higher intakes of iodine, there is much, much more controversy. Some practitioners seem to advise intakes of a hundred times the "official" standard requirement of around 150 micrograms a day. Or more.
Personally, I find it stretches my credulity that such high doses are safe and good practice. But that is short of me saying it is definitely not the case.
And we have seen a number of members having issues with high iodine intake in the form of medicines like amiodarone and X-ray/CT contrast agents.
What is clear is that there have been quite a number of papers in the recent past questioning the safety and advisability of "excess iodine". Each paper defines that in its own way. And some papers might simply contain the words and not be relevant. Some papers might even support high doses of iodine.
The search below finds over 32,000 papers but I doubt more than the first few hundred are worth looking through!
This is being posted in the spirit of pointing out some papers exist. And leaving anyone who is interested to know of them and to read, if they wish. Beyond my choice of search term, the data is obviously entirely unfiltered. It might include pre-prints, and other lower status papers as well as top quality research papers.
Excess iodine promotes papillary thyroid carcinoma through the AKT/mTOR pathway
A new LNC89/LNC60-Col11a2 axis revealed by whole-transcriptome analysis may be associated with goiters related to excess iodine nutrition.
Chronic Excess Iodine Intake Inhibits Bone Reconstruction Leading to Osteoporosis in Rats.
Excess Iodine Consumption Induces Oxidative Stress and Pancreatic Damage Independently of Chemical Form in Male Wistar Rats: Participation of PPAR-γ and C/EBP-β.
The Role of Thyroid Hormone Synthesis Gene-Related miRNAs Profiling in Structural and Functional Changes of The Thyroid Gland Induced by Excess Iodine.
Excess iodine exposure acutely increases salivary iodide and antimicrobial hypoiodous acid concentrations in humans.
Protection of Vitamin C on Oxidative Damage Caused by Long-Term Excess Iodine Exposure in Wistar Rats.
Excess Iodine Exposure Acutely Increases Salivary Iodide And Antimicrobial Hypoiodous Acid Concentrations In Humans
SAT-442 The Impact of Chronic Excess Iodine Intake in Adult Mice Behavior
Long-term repetitive exposure to excess iodine induces mitochondrial apoptosis, and alters monoamine neurotransmitters in hippocampus of rats of different genders.
Excess iodine impairs spermatogenesis by inducing oxidative stress and perturbing the blood testis barrier.
Excess iodine intake: sources, assessment, and effects on thyroid function.
Excess iodine-induced lymphocytic impairment in adult rats.
Relationship between excess iodine, thyroid function, blood pressure, and blood glucose level in adults, pregnant women, and lactating women: A cross-sectional study.
Non-immune-related hypothyroidism and its relationship with excess iodine.
Risks of excess iodine intake in Ghana: current situation, challenges, and lessons for the future.
Hypothyroidism in Infants With Congenital Heart Disease Exposed to Excess Iodine.
Effect of excess iodine intake on thyroid on human health.
Consequences of excess iodine.
An investigation into the effects of maternal supplementation with excess iodine on the mechanisms and impacts of reduced IgG absorption in the lamb postpartum.
Effect of Excess Iodine Intake from Iodized Salt and/or Groundwater Iodine on Thyroid Function in Nonpregnant and Pregnant Women, Infants, and Children: A Multicenter Study in East Africa.
A comparative study on the effects of excess iodine and herbs with excess iodine on thyroid oxidative stress in iodine-deficient rats.
Subclinical Hypothyroidism and Elevated Thyroglobulin in Infants with Chronic Excess Iodine Intake.
Effect of excess iodine intake on thyroid diseases in different populations: A systematic review and meta-analyses including observational studies.
The relationship between excessive iodine during pregnancy and adverse pregnancy complications.
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