That's really interesting, to me anyway.
While I had thyroid cancer, I had to have radioactive iodine treatment twice. Prep for this was to eat an iodine-free diet (or as close as possible) for the 2 weeks prior. There's a US organisation for thyca patients that publishes a free cookbook for these times, and from the mailing list it appears that some US patients have a really hard time avoiding iodine. I presume that's the case for many elsewhere too, but tbh it was dead easy for me (e.g. we bake our own bread and have sea salt at home).
Based on that, I do wonder whether we have an iodine-deficient diet already.. but I haven't seen any signs or problems in DD or hubby (is not such a big thing for me any more).