I take a thyroid "support" mix and vitamins for some of my deficiencies. The thyroid support is from Thorne Research, the company seems reputable and I am sure there are others. I was deficient in so many things due to hypo and stomach issues I decided to try thyroid support. So far so good.
From what I can find, there is no real science to back up some of what's in the book referenced above...
Supplements advices by (Thyroid Pharmacist, Dr. Izabella Wentz) helped me allot.. Check out her Facebook page and book "the root cause"
That depends on rather or not you have Hashimoto's Thyroiditis, which is the most common cause of hypothyroidism...