Posted on 06/16/2020 12:22:45 PM PDT by ConservativeMind
Abstract
Iodine is a trace element that is essential for the synthesis of thyroid hormones in the thyroid gland. Evidence suggests that excess iodine intake exerts a triggering effect on the development of autoimmune thyroiditis (AT), with many studies reporting a rising incidence in iodine sufficient countries. Processing excess iodine in thyroid follicular cells, during thyroid hormone synthesis, may result in increased amounts of reactive oxygen species, leading to thyroid cell damage and the triggering of thyroid autoimmunity. Another trace element, selenium found in high amounts in the thyroid, is very important for thyroid physiology. Selenium is incorporated into selenoproteins that are involved in the protection of thyroid cells from oxidative damage, incurred by exposure to hydrogen peroxide (H2O) originating during thyroid hormone synthesis. Population studies suggest an increased prevalence of thyroid autoimmunity in areas following iodine fortification, and a possible protective effect with selenium adequacy. In animal models, selenium has been shown to reverse the induction of autoimmune thyroiditis caused by excess iodine intake. It appears therefore, that an optimal balance between iodine and selenium is important for maintaining normal thyroid function, and that the loss of such balance in favor of iodine, may play a role for the rising trend of autoimmune thyroidits, currently seen in iodine sufficient countries.
Conclusions and future perspectives
Evidence from clinical research suggests that excess iodine intake can act as an environmental risk factor for the development of autoimmune thyroid disease in populations of iodine sufficient countries. Similarly, in animal studies high iodine intake may exacerbate a pre-existing autoimmune thyroiditis. It is believed that redundant H2O2 are generated during oxidation and organification of excessive iodine in thyroid cells, leading to elevated oxidative stress and resulting in oxidative cell damage. However, this may occur only if selenium is deficient. Optimal selenium intake exerts a protective effect against iodine- induced oxidative cell damage by enhancing glutathione peroxidase activity and providing antioxidant protection to the thyroid cell. It appears, that selenium status may play an important role in preventing iodine- induced AT, and that an optimal balance between iodine and selenium is important for maintaining normal thyroid function. It can, therefore, be concluded that an iodine to selenium imbalance, in favor of iodine, may be responsible for the rising trend of AT in iodine sufficient countries. At a clinical level, studies have shown that selenium administration may improve autoimmune laboratory parameters in patients with established AT.24 Further studies are awaited to demonstrate the impact of such intervention in modifying the natural course of thyroid autoimmunity. It is tempting to speculate that, the real impact of selenium would be in preventing the manifestation of AT in those individuals at high risk of developing the condition, after exposure to high iodine intake. Thus, in implementing future iodine prophylaxis programs, balancing the effect of iodine with concurrent selenium administration, is expected to have a favorable outcome on the risk of AT.
Ping to you on post #20.
Sorry, to post #19.
if you’re in the midwest take selenium
the soils here are deficient, most people here have a deficiency of it and require supplementing
I love shrimp and lobster, but you can keep your seaweed.
Taking too much selenium can increase your cholesterol by almost 10 percent.
what’s too much?
This has probably already been posted on FR but here’s an article discussing an association between selenium status and COVID-19.
https://academic.oup.com/ajcn/article/111/6/1297/5826147
From this article:
https://www.livescience.com/43566-selenium-supplements-facts.html
“The Institute of Medicine’s Food and Nutrition Board caps the safe daily intake of selenium at 45 micrograms for infants, 60 to 90 micrograms in toddlers, 150 to 280 micrograms in prepubescent children and 400 micrograms in adults.”
That article references many studies, but most don’t give a dosage.
I don’t know what’s too much selenium but I have read, I think it was Dr Mercola, the best source for your body is to eat two Brazil nuts per day. No more than two.
Thank you for that. I have not seen it posted here.
How do you know that this paper isn’t correct and either lack of selenium or too much iodine, with both creating an imbalance, isn’t the cause?
bkmk
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