I don't know how to answer your question, but do recall reading this recently about those that have issues with iodine. Hope it helps!
"Thyroid Tune-up Checklist"
"Iodine is not optional; it is necessary for health, including breast health, oral/gastrointestinal health, and the health of a developing fetus. The RDA for non-lactating adults is 150 mcg per day, the quantity required to not have a goiter, but not necessarily ideal thyroid health. I?ve therefore been advising 500-1000 mcg per day from an iodine supplement, such as kelp tablets (dried seaweed), available at health food stores (not pharmacies). The only adverse effects of iodine arise in people who have inflammatory thyroid disease, such as Hashimoto?s thyroiditis, unsuspected thyroid nodules, or longstanding and severe iodine deficiency. In most cases, very low doses of iodine, e.g., 100 mcg per day, can be introduced and increased gradually over months. (Ideally, this would be undertaken by your healthcare provider, but good luck finding one knowledgeable about iodine.)"