Iodine Dosing

I am wondering if it's necessary or beneficial to be dosing iodine. I have had two ICP tests done on my tank lately, and in both the iodine levels were approximately 20.85 µg/l (which ATI said is critically low). I am hesitant to do it since I know it is an easy element to overdose and except an outbreak in cyano, my tank hasn't been experiencing any issues. The tank is also about 4 years old and 60 gallons total water volume if it helps