Where to find iodine suplement?

Hi,

I just found out that my local LFS has ghost shrimps and Newts.
They are cute the newts.

Anyway I am interested in the shrimp. I always wanted to have some kind
of "lobster" in my tank.
Crayfish are too agressive so the other choice would be these shrimp.

I did some research and they seem to need iodine in the long run.
My lfs in the area do not carry what is mentioned alot kent Marine
Iodine or any other brand with Iodine on it that I could find. So I am
turning to something else that could provide iodine to them because I
really want to get those shrimp.

So besides pure iodine what can I put in the tank to suplement?
I even looked at the food but none mentions iodine in their ingredients
list. I wonder if foos with shrimp in it would provide that like dried
brine shrimp or something?