100mg is nothing when using sski (potassium iodide), but it is very high when using lugol's long term.
I have used as much as 5gms per day for 5 days of sski, but only took 100mg daily of Lugol's 5% for a month.
Different tissues has different preferences of iodine, for ex:
Thyroid needs 3% prefers iodide (50mg iodide)
Lungs prefer iodide
Skin needs 20% and prefers iodide (400mg iodide)
Salivary Glands prefer iodide
Muscles (650mg) and fat needs (700mg iodine) 70%
Breast tissue needs 3-5 mg / day minimum and prefers iodine
Prostate prefers iodine
Stomach prefers iodine
Entire body needs 1500 mg - 2gm total
Body's Daily Iodine Need:
Thyroid needs 6 mg iodide /day
Breast needs 5 mg iodine /day
Other tissues needs 2 mg/day
(adrenals, thymus, ovaries, hypothalamus, pituitary and others)
Look at page 13 of this pdf
https://optimox.com/pics/Iodine/pdfs/IOD01.pdf
This shows you high doses of iodine and their effects.
Going above 175mg inorganic iodine can cause issues especially long term.
I think that if someone is not getting a good benefit from 25-50mg daily, they should had a couple grams of potassium iodide.
Potassium iodide is the salt of iodine.