Low TSH,should I decreased synthroid as Endo suggested?

[Wirewaist2]

6/20/14, taking 75mcg of Synthroid.

9/6/14, decided to add 5 mcg of Cytomel, after new lab results showed a decreased in FT3.
Changed mind, due to FT4 also not being in midrange.  Felt it was best to continue raising levels before adding Cytomel.

9/8/14 Med was increased to 100mcg.
10/21/14, labs drawn
10/27/14, lab results since the increased.      
TSH     0.049 u/ml   (0.450-4.500)
FT4      1.17 ng/dl    (0.82-1.77)
FT3      3.4 pg/ml     (2.0-4.4)
Vit D     42.8 ng/ml   (30.0-100.0)
Fe         59 ug/dl       (35-155)
Ferritin  48ng/ml       (15-150)
B12       1021 pg/ml  (211-946)
Just heard from my Endo, wants to decreased Synthroid to 88mcg.  Says TSH is too low.
Not sure what to do, read that low TSH can cause cardiac and bone mineral density problems.

[Wirewaist2]

Thanks barb, much appreciated.

[Barb135]

If your vitamin D isn't coming up after being on 5000 IU for 3 months, you might need to talk to your doctor about trying a higher dose.  Yes, you want to get your level pretty high in the range, and for some reason it seems like yours might not want to go up very badly.

You're right that low levels of FT3 can be associated with lingering symptoms, however, I think your FT3 is tracking your FT4 up nicely, so it doesn't look like you  have a conversion issue.  It looks like it's just a matter of getting/keeping your FT4 high enough to get your FT3 up where it needs to be.  

Typically, cytomel or other T3 med is called for when FT4 levels are high in the range and FT3 levels are lagging way behind toward the bottom of its range.   FT3 should be higher in its range than FT4 is in its range and yours is just about right.  When your FT4 is at mid range, we'll have to see where your FT3 is in relation to it, then we'll know if you need cytomel.

[Wirewaist2]

Hi Barb,
My vitamin D levels fluctuates between 20-44.4 ng/ml.  The highest was 44.4ng/ml.  It has now drop down to 42.8.  I have been on 5000 IU for about 3 months and it has not risen above that level.  I read where the goal should be about 50-80 for hypo individuals.  The cytomel comment was a miscalculation on my part of the FT3 level.  I also thought lower levels could be associated with lingering symptoms.

[Wirewaist2]

Hi Barb,
My Vitamin D levels fluctuates between 20-44.4 ng/ml.  The highest was 44.4ng/ml.  It has now drop down to 42.8.  I have been on 5000 IU for about 3 months and it has not risen above that level. I read where the goal should be about 50-80 for hypo individuals.   The cytomel comment was a miscalculation on my part of the FT3 level.  I also thought lower  levels could be associated with lingering symptoms.  

[Barb135]

Good that your endo agreed to let you stay at the 100 mcg level for a while; there's no reason for you to decrease your dosage when you aren't hyper.  As long as you aren't experiencing hyper symptoms, I think 3 months is a reasonable time between visits.  That's typical once levels start stabilizing; eventually, she will probably drop that to every 6 months.

Good that you're on the vitamin D.  5000 IU is pretty high dose, so make sure your levels get tested periodically, since vitamin D can be toxic if you get too much.  You're on track with the iron supplement, but keep track of your ferritin levels to make sure you keep tracking up with it.

I'm not sure why you want to add cytomel in the future.  With your FT4 at less than mid range and your FT3 in the upper half, it looks like you're converting just fine.  Lack of conversion from FT4 to FT3 is the most common reason for needing to add a T3 med.  If you're converting adequately, there's really no need. You need to bring up your FT4 level and see if your FT3 continues to track it up.

[Wirewaist2]

Hi Barb,
Again, thanks for helping me make sense of it all.  My endo agreed to keep me at 100 mcg for a while.  She suggests that should I experience any hyper symptoms to let her know.  She wants me to stay at this dose and see her in three months with lab results.  Do you think that is too longer wait? I am supplementing with liquid vitamin D 5000IU.  I also take an Fe supplement, 22mg, but this is non hem vegan base.  I am not completely symptom free, and would like to add cytomel in the future.  Any thoughts on that?
Thanks again.

[Barb135]

Low TSH will not cause cardiac issues or bone mineral density problems... my TSH has been at < 0.01 for the past 6 yrs and I've actually rebuilt bone lost to osteopenia (pre-hypothyroid), via a regimen of calcium, vitamin D, magnesium and exercise.  In addition, all 4 of my heart valves leak and I have no problems with them, nor do I have any other cardiac issues.

If you don't have hyper symptoms, you're not hyper, just because your TSH is lower than normal... that's very common when one is on thyroid replacement. If your endo doesn't know that, you might need a different one!!

That said, looking at your FT levels, you really need to stay at the 100 mcg level for a while.  Your FT4 is only at 37% of its range - recommended is mid range. Your FT3 is only 58% of its range and recommended is upper half to upper third of its range.  

Your vitamin D is on the low side - are you supplementing that? You should try to get it up into the 50-60 range.  Your Ferritin is also too low.  Ferritin is an iron storage hormone and low levels indicate that your iron level is being depleted, even though yours is in the normal range.  Exact Ferritin level is somewhat controversial, as different sites recommend different levels, but I'd say you should get your level to at least 50 and preferably higher.  

Your B-12 is fine - even though it's over your lab's range,  many labs use an upper limit of 1100, so you're good... B-12 isn't toxic, so you just eliminate excess in urine.

If you don't have any hyper symptoms, I'd resist decreasing thyroid med, based on TSH levels... hope this gives you something to argue with..