I am trying to determine if I should seek supplemental sources of iodine in my diet (and my family's diet). Overall I rely on kosher salt in my cooking, which as I understand it, does not have iodine. However, we all regularly consume salted Kerrygold butter, though I have no idea whether this contains iodine.
Otherwise, our diet often contains organic whole milk yogurt, organic whole cow's milk, organic eggs, fish of various types, strawberries and mozzarella cheese.
I'm not opposed to adding kelp type sources to my diet, but would probably only consciously do so if I had reason to believe I was iodine deficient.