iodine purchase in uk

Hi,
I realize this is probably in the top ten, or even five, silly questions to be asked on this forum, but I have no choice.

WHenever I search for Iodine I get either water purification iodine, stuff for fish tanks, or kelp.

Is there anyone in the UK who can give me a supplier and product to buy? I really think I need this stuff for hypethyroidism. It helps with that, right?

Thanks.

Fiona