People who have thyroid issues (hypothyroidism) will learn that artificial source of iodine are not great for you. Your thyroid is responsible for converting iodine minerals you consume into thyroid hormones. These hormones are important for a wide range of metabolic function, like growth, bone, and brain function. A thyroid imbalance basically throws your whole body off.

While artificial iodine may be tolerated by most people, those with thyroid disease are best to avoid the very difficult-to-process forms of artificial iodine's like they are poison. Since avoiding it is very difficult, one usually mostly switches to non-iodized salt, by sticking with sea salt, and ordering low salt foods when eating out. Plenty will still be in everything, but this can blunt the edge.

Instead, it is best for you thyroid to get iodine from natural sources. It is in a lot of things, but if you really need more, you might try a diet including some foods known to be iodine-rich, such as seaweed (I guess people eat that, lol), fish, shellfish, crabs (it seems like most salt-water seafood), dairy (whole milks and cheese), eggs, yogurt, prunes, Lima beans, and there are plenty others.

Taking too much iodine can be pretty bad for you too, especially on a long term basis. It can cause burning of the mouth/stomach, stomach pain, fever, diarrhea, and vomiting; basically a very bad time. Then, long term, it can lead to thyroiditis or various types of thyroid cancer.

Potassium iodide is best know for the iodine pills you take during a nuclear emergency, to block your thyroid from in-taking radioactive iodine. It's also used to treat lung breathing problems like asthma, bronchitis, and emphysema...which reminds me I don't remember hearing about its use during Covid.

There are several things that are a specific risk for taking potassium iodide, which includes about anything that involves itchy skin, hives, or skin soars, like specific diseases. Another is celiac disease, where you aren't supposed to eat gluten. A wide variety of heart problems and thyroid problems are also reason to stay away. These must be quite concerning, as they tell you to skip the potassium iodide pills during nuclear fallout.

Iodine allergies do exist and although it seems unlikely, iodide and iodine can be tolerated differently as an allergen.

I like these topical mineral ideas, as they seem much less risky then orally taking something. They are much harder to overdose for sure. My wife is all into topical magnesium; lotions, creams, and stuff. She says it really helps with back and muscle pain/cramping. She had some pretty bad back problems for a bit, so I've gotten use to the magnesium smell, lol.