Using Dar's lead, I traced the statement to "Orthoiodosupplementation in a primary care practice," by Dr. Flechas, Original Internist, June 2005. It's on the Optimox site as well. At the following link, it's in the second-to-last paragraph on the first page. On this link, the reference given is (7), but the references aren't numbered. On the Optimox site, they're numbered, and (7) refers to Williams Textbook of Endocrinology. If Williams is the correct reference, it should have the original reference, but I can't find it.