Q. I heard that if you ingest too much iodine, you can develop hypothyroidism. Is that true? I’m a little confused about why that would happen .
A. Yes – it is true that too much iodine can lead to hypothyroidism. It seems counterintuitive; you’d think that more iodine would lead to more thyroid hormone production. However, it does seem that there is a link between excessive iodine intake and autoimmune thyroid disease (leading to hypothyroidism).Recently, researchers from China have found that too much iodine leads to an influx of lymphocytes, for some reason, and an increased incidence of self attack on the thyroid:
“…although iodine supplementation should be implemented to prevent and treat iodine-deficiency disorders, supplementation should be maintained at a safe level. Levels that are more than adequate (median urinary iodine excretion, 200 to 299 µg per liter) or excessive (median urinary iodine excretion, >300 µg per liter) do not appear to be safe, especially for susceptible populations with either potential autoimmune thyroid diseases or iodine deficiency. Supplementation programs should be tailored to the particular region. No iodine supplementation should be provided for regions in which iodine intake is sufficient, whereas salt in regions in which iodine intake is deficient should be supplemented with iodine according to the degree of iodine deficiency.”
The underlying mechanism hasn’t been entirely worked out – but there does seem to be a link. So: adequate (but not excessive) iodine supplementation is important in iodine-deficient regions, whereas people in iodine-rich regions should not ingest additional iodine.
- Dr. Sofi said Nicely explain
- s.sahu said very useful. simple points but very important
- Galen Ballentine said So good thank you!
- yvony said Just for clarification, how to get percentage from absolute count? ….you have given an example...
- yvony said very informative
- Kristine said Thank you!! I can’t wait 🙂
- Dental Student said This was amazing! Thank you for being so devoted. I can tell it is going to be a great semester. See...
- Senthil said Really awesome explanation. Keep the good work going!!
- Shirouh said Thanks alot its very helpful for my upcoming end exams
- Monica Austin said Very helpful. Thank you.
- Jean said Amazing explanation, already had an idea, well elaborated and segmented to maximize understanding. G...
- Christine said This is a fantastic review for the ASCP MLS exam! Thank you!