Iodine for an 18mos old?

So, I have been curious if its safe to give a baby iodine? Our son is adopted, we have had him since he was 3 days old. He was drug exposed during the pregnancy (for 9 months) to meth. He is very normal and healthy now....you would never guess he has the past he has. I thought Iodine might be good for him. Any recommendations? I am slightly concerned with detox problems because of the 9mos of drug exposure.
Let me know if there is any ideas for him! Thank you.