First, my personal experience:
I have had to avoid iodine altogether because of sensitivity, caused by using it to disinfect my drinking water back in the 1980's. It took only 4 weeks of weekend hiking before i broke out in an nasty, all-over, deep-seated rash (lichen planus) which itched horribly and left permanent scars. I wouldn't wish this experience on my worst enemy! Since then I've had to avoid all iodized salt, seafood, mutivitamin/mineral supplements containing iodine and any other foods containing iodine (many energy bars have it added). Even tiny amounts will trigger the rash. Basically, I have to (1) Carefully read labels on everything; (2) Avoid seafood altogether--including salmon; (3) Avoid restaurant food unless they confirm they use non-iodized salt or I order foods that can be prepared at the last minute without salt (often I'm stuck with green salad with oil and vinegar); (4) Turn down invitations to meals at the homes of friends or relatives unless they assure me that their food is prepared with non-iodized salt.

Second, the Agency for Toxic Substances and Disease Registry:
Quote:
Iodine is needed for your thyroid gland to produce thyroid hormones. You and your thyroid gland are healthy when there is just enough iodine in your body, about 10�15 milligrams, so that just the right amount of thyroid hormones are produced. This amount would look like much less than a pinch of table salt if if placed in your hand. This amount of iodine is in most people when they eat the foods that people normally eat in the United States. Your thyroid gland can become unhealthy if more or less than this amount of iodine is in your body. An unhealthy thyroid gland can affect your entire body.

Per the CDC's Water Disinfection for Travelers:
Quote:
Because iodine has physiologic activity, WHO recommends limiting iodine water disinfection to a few weeks of emergency use. Iodine use is not recommended for people with unstable thyroid disease or known iodine allergy. In addition, iodine should not be used by pregnant women because of the potential effect on the fetal thyroid.
[emphasis mine]


Edited by OregonMouse (03/28/16 06:37 PM)
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May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey