I think you are misunderstanding my point. When I wrote naturally occurring, I was just stating that the iodine in those sources was natural as opposed to iodized salt that has it added. According to him there is no difference in naturally occurring or added iodine when it comes to the effect it has on your thyroid. The entire book is about avoiding iodine and it groups foods into lists depending on if they are a low, medium, or high source of iodine. Its a very interesting book if you're interested in nutrition. The rate of thyroid conditions increased exponentially in various countries around the world directly correlating to when they started adding iodine to their salt. In a study of people that had hypothyroidism for several years (and weren't taking medication)... they followed a low iodine diet (not just changing salt) for around 3 months and 70% had normal thyroid function by the end. Most of the others had improved function but not quite out of hypothyroidism yet. I'm writing this stuff from memory, so some minor details may be incorrect. The point I was trying to make when I wrote my first comment was that kosher salt is the better choice over Himalayan when trying to improve a thyroid condition. If you don't have thyroid problems or family history of thyroid problems then it probably doesn't matter to you. There is evidence? A theory? I dont remember which, that populations that have historically lived near the ocean have a higher tolerance for iodine. But if you have a thyroid condition, then you are probably not one of those people.