How do I convert my T4 dose to NDT?
This is a question one sees often in the thyroid Facebook groups. There is a lot of confusion and insecurity around this. Which is not so strange, as there is very little good info on the topic. The conversion tables the NDT (thyroid) producers themselves provide are ridiculously low. They are wrong, wrong, wrong. I don’t understand how they think at all. If they do. Think. One would be seriously under dosed if adhering to those guidelines. And if one’s doctor reads them, one could get serious problems. I don’t know how many doctors read these instructions. I hope they don’t. Here is a table from Nature Troid as a (bad) example.
I have translated some of Thyroid Patients Canada’ articles on conversion into Norwegian. These articles are very interesting, esp this one, https://thyroidpatients.ca/2019/11/12/the-basics-of-thyroid-hormone-action-transport-and-conversion/
Most of the hormone conversion, T4 to T3 happens outside the thyroid. though there are big individual differences how much. There are 3 enzymes responsible for this conversion, D1, D2 and D3. They do a lot more than convert T4 to T3 though.
This is not really a post. I have translated Tania Sona Smith’s article, https://thyroidpatients.ca/2019/11/25/free-t3-peaks-and-valleys-in-t3-and-ndt-therapy/ , into Norwegian. For every Norwegian page, I want there to be a corresponding English, and vice versa.
This is just a presentation of Tania’s piece. She is looking into the reseach on how Ft3 behaves after dosing with T3 containing medicine. Actually, there is not really any good studies on the subject . There is a study on FT3 after a single dose of T3. But that is not what most people take when dosing with T3. We do multidoses. There is no study on FT3 when multidosing, but there is one on T3, that is total T3. Where I live in Denmark, we cannot have FT3 tested. The endoes have forbidden it, they claim, FT3 fluctuates too much, it cannot be trusted. How do they know? With no studies? Anyway, FT3 and T3 follow each other in most instances . With a very important exception, when we take estrogen orally. Then both T4 and T3 becomes higher and FT4 and FT3 lower. So VERY important to have the frees tested.
This is just a short abstract of Thyroid Patients Canada’s article on Triac, https://thyroidpatients.ca/2020/01/02/when-dosing-t3-you-get-higher-levels-of-triac/ . I just want to draw your attention to this metabolite. The quistionmark on the image, is meant to signify my surprice when learning of Triac. I had never heard of this thyroidhormone metabolite until I read Tania’s post. It is quite strange, as it has been studied since the 1950ies. I don’t think many of our doctors have ever heard of it.
So what is it? It is a thyroidhormone metabolite like FT4 and FT3 are. It acts much as FT3, it’s abbreveration is TA3. It has a much shorter halflife than FT3, about 6 times faster.