I can only tell you that I was Led to answer you in this way:
The baby growing inside of [you] will ONLY take what he/she needs; any extra will be used by [YOUR] body (if it needs it) and eliminated if [your] body does not.
That's pretty darn close to how I 'received' the information, so, no, I didn't read it from a book. It felt important to tell you, and like I would be 'wrong' if I didn't tell you.
Congratulations on the pregnancy!
I was at a birthday party yesterday. Our young neighbor turns 1 on Tuesday. He's so darn cute - I keep trying to tell his mom about iodine, but...
...oh it breaks my heart - I'm SO happy you have such a healthy iodinated child.