for iodine you really should get your pee tested using dosing challenges and use actual lugols... 225mcg is nothing... i have full strength lugol's and i can dose 5 drops (20mg/drop 15% KI3 so 3mg/drop or 15mg) but i already started on this years ago and i skipped the tests by piling on salt to allow my kidneys to rapidly eliminate any excess anything

what you get with iodine is it loosens up the buildup of fluoride and bromides that have built up due to water and stuff like fire retardants in plastics, and these cause symptoms of anxiety and sleepiness, respectively, unless you eliminate that garbage fast... so in other words, yeah, if you are toxic with halides you need to be really careful, but 225mcg is nothing, you will get as much as that by eating cod fish steaks a couple times a week

the magnesium, glycinate is one of the best, the chelate is also good, but anything that is mostly carbonate or citrate is not well absorbed, and this problem is worse if you have IBS, it is the slowest absorbed... citrate is better than carbonate but neither are easily absorbed

if you feel you have symptoms of magnesium deficiency, likely you are also suffering calcium deficiency because there is a rate limit between those two (the kidneys eliminate calcium when there isn't enough magnesium) and further, magnesium is eliminated if you don't have enough boron... look into boron supplementation, doesn't cost very much, at pharmacies you can buy little ounce sachets of it, put one of those in a gallon of water and drink 25-50ml (1-2oz) of that per day - the only thing i can mention about being careful with boron is that it can dramatically increase your appetite, but it definitely fixes Ca/Mg deficiency if you have it