kids are pretty hardy, they only need dosages adjusted for age / weight IMO.
To avoid hypo T / hyper T disturbances I would add selenium.
Mind you that in my country the soil is very low in Se, while in parts of US it is high. I would adjust to this fact.
Anyway a 100 mcg of selenium methionine is protective; if they ever eat fast food / vegetable oil etc.
maybe 3-5 days out of the week. I cant give you exact measures, in that case I would need to know more about every each of them and a detailed diet.
Most are deficient in magnesium. I was for years, my youngest one that was most suffering of my border hypo T as pregnant; ask for it once in a while. When he has growing pains, crampings etc. Doesnt happen much nowadays as he has some almost every day he stays with me (every second week)
In kids magnesium deficiency can be shown as growing pains, insomnia, hyperactivity, cramping, convultions, overactive bladder etc.
Adding a pinch of borax (cosmetical grade) in food or juice is simply balancing magnesium vs calcium. + fixing enuresis and UTI almost overnight if that is an issue.
+ fix eye infection in a day or two.
Vit B and C I have to supplement with, even with the best of diets I havent managed to be sufficient.
(yes I have been through a long phase of only natural supplements, actually the year when I got hypo T)
- my kids get this as a supplement too; 1-2 gram of vit C, they are 12 and 15. Some vitamin B, not daily, but now and again.
Salt; we use it deliberately in food; and if head aches, they seek out the salt pot themselves. Again, that doesnt happen much lately.
I believe you are concerned that you may hurt your kids with iodine, I was too; a good mother should be.
I am four years into it and all I can say is they have become smarter and more in balance; my eldest found out within a year or two that the Iodine had an inpact on his IQ; that impressed me quite a bit.
I would go low and slow in the beginning; I did. No rush.
Sprinkle in food /drinks, when 8-10 years of age they can usually take capsules.
ps. milk, juice, tea; totally cover the taste of iodine.