Gary Krieger says, "What might cause high-normal range TSH, T4, reverse T3,
and free T3, good free T3, not lowering TSH? Does T3 negative feedback
to lower TSH occur in T4 as converted T3 or after T3 uptake in the cell?
Thank you." So Gary I believe your question is if your teeth if you're free T3 looks
good why use your TSH still a little high why hasn't the T3 brought it down
enough well actually 90% of the and let me back
up for people who aren't familiar with this so your your thyroid wind makes
thyroid hormone thyroid hormone increases your metabolic rate and does a
lot of related things and your hypothalamus is governing that by
controlling your pituitary the master ended endocrine gland and it's secretion
of TSH which is what controls the thyroid gland makes it make more thyroid
hormone so the way that the feedback occurs is that the circulating t4 is
inside the cells of the pituitary converted to t3 and that that is what
suppresses the production of TSH which is basically the pituitary is monitoring
the thyroid hormone levels to know whether the thyroid has done its job so
if the pituitary the master endocrine gland is gland decides that the thyroid
has done its job it takes down TSH the signal to make more thyroid hormone so
if so you really are not looking at whether the free t3 is suppressing the
TSH 90% of that suppression comes from circulating t4 that's converted at t3
inside the thyroid gland so you really are looking at whether the t4 is on the
high end of normal or not and if it is on the high end of the of normal and the
TSH is still a little high then that to me indicates that
um and it's not clear to me from your question whether the reverse t3 is on
the high side of normal as well or if you meant that they were all good
meaning the reverse t3 is low so if your reverse t3 is on the higher end of
normal then that explains it your body is you basically have your brain telling
your thyroid gland that it needs more thyroid hormone but you have much of the
rest of your body deciding that it can't it's not in the position to carry out
the effects on the metabolic rate that the thyroid hormone is demanding and so
it's converting the the the thyroid hormone into reverse t3 which is
basically a thyroid antagonist so so if you're rusty 3 is high then I think you
want to look at things like calorie intake carb intake and stress levels
because I think those are the main things that might make your body want to
resist the signal of thyroid hormone by making the reverse t3 if the reverse t3
is good meaning it's pretty low then I think that means that there's something
either in your brain specifically in the hypothalamus or in the pituitary or
somewhere in the combination where they're just deciding that your body
needs more thyroid hormone than you have and
and I my suspicion is that that's gonna relate to how sensitive your cells are
to the thyroid hormone if you're sitting here if your cells are somewhat
resistant and remember in the last AMA this got brought up and I talked about
zinc deficiency and high free fatty acids being the primary things that are
gonna reduce sensitivity to thyroid hormone or cellular uptake so it there's
some indications that high free fatty acids might also decrease cellular
uptake but not much is known about what governs cellular uptake and in fact
there are some genetic variations in cellular uptake so if the thyroid
hormone levels are high in your blood because because they're not getting into
the cells the Mac could easily explain everything it's just that your problem
seems pretty moderate because you're not saying that your thyroid hormones are
sky-high and your TSH is sky-high you're just saying everything's a little
on the high side of normal so it sounds like there's not a big problem but that
your body does 1 something somewhere is your body is determining that you need a
little bit more thyroid hormone and so if you can address the same free fatty
acids and
I would I would address zinc and free fatty acids as the top things unless the
reverse t3 sio target carbs calories and stress alright Gary I hope that helps
thank you for your question