Reduce a goiter naturally?

I have a goiter on my neck that is very unsightly. I have been to my primary doctor and a thyroid specialist. I was told my thyroid is functioning properly and all blood work has come back normal. The thyroid specialist basically said my goiter was unsightly, but not malfunctioning so he is taking no further action. I want to reduce my goiter naturally. Any useful suggestions?? I cannot buy just iodine supplements (I have looked), so please give another suggestion. Thank you.