I have the EXACT same health history as you, even down to the treatment and vit D. I was told that lead can impair vit D metabolism and block thyroid hormone receptors. My doctor and I both think that this was why my thyroid blood levels were elevated (to more levels) after taking medication yet I was still feeling awful. I am saving up for EDTA (chelation treatment) to remove the lead. I will let you know if this resolves my thyroid issues. Does anyone have any insight into this problem, or perhaps information on cheaper treatments to remove lead.