The info I got re iodine was that it should be taken with Selenium and 
Selenomethionine form was the best for absorption.I get it from iHerb.

Tried Knox gelatin first, in water,ghastly stuff;was put onto “Great Lakes 
Gelatin” O Bloom gelatin.Great stuff.Go for good old Googling .Have to order it 
by ‘phone tho.I get it in bulk,10 lbs at a time.
Put it in my coffee ,2 tspns per cup,1 tspn in tea per cup, never know it’s 
there,add it to my soups.Helped get my walking cane out of my hand a few years 
ago,don’t need it now !!
Best to all.
Harold