Fun fact: Iodine is critical for treatment and prevention of radiation sickness. In the event of a nuclear incident, they used to issue iodine tablets as part of the NBC warfare kits, and they were included in the supplies of the civil defense fallout shelters. By flooding your system with clean iodine, it prevents the thyroid from taking up radioactive iodine from the fallout. It is also a pretty good disinfectant for minor cuts and abrasions, with the side effect of giving your body an essential nutrient rather than poisoning it. Funny how it disappeared from store shelves once big pharma spread it's tentacles throughout the FDA. (It can't be patented, but iodine with unnecessary poisonous additives can). Fortunately, you don't need a large amount of iodine to flood your thyroid, even Betadine contains enough iodine to do the job with just a patch of it placed on your skin, about the size of your palm. A couple drops of pure iodine in a few ounces of water is way more than your body needs, or your thyroid can even store, and is a waste, you'll just piss it out. That's a strong enough solution to use as a water purification mix. You especially don't need to do that every day, unless you're drinking swamp water. One drop will flood your thyroid, with plenty left over. From there, just eat a bit of kelp or other iodine rich foods at least once a week, and you'll do much better than about 95% of the population. If you can't get those, add one drop of iodine to a pot of healthy stew now and then. (Real iodine, not the poisoned versions like Betadine etc.)