I have already asked the question on Quora in the past, yet I have not received satisfactory answers. See the link here.
I'd like to consume miso soup often, however, the dashi for the soup (Japanese broth, the basis of many Japanese soups and sauces) is made from boiled kombu seaweed, which is very high in iodine.
I have read that if one pre-soaks kombu in water it removes a lot of iodine, yet does not comprise the taste much, however I was not able to locate the daily recommended dose of dashi made from kombu, nor any other recommendations (e.g. use kombu 2x10 cm long, boil for 20 seconds - this will be approximately 60% of your iodine daily intake).
Also, the Japanese often eat tofu and other foods that contain several chemicals that suppress the high iodine intake, though, again, no real numbers.
Are there any real studies/numbers on this? Of course, the iodine concentration in such broth strongly depends on the kombu used, the length of boiling etc., yet I believe there must be some average values one can take into consideration in order to maintain thyroid health.