Have you ruled out hyperparathyroidism? If not check your serum calcium and PTH together as creating problems when taking Vitamin D seem to be due to hypercalcemia.
Make sure you take levothyroxine on empty stomach and give sufficient time before taking food and other supplements.
I have had a test for parathyroid last fall, and a calcium test earlier in the year:
4/13/16 calcium 9.6 mg/dL (range 8.5-10.5 mg/dL)
8/10/16 PTH 20 pg/mL (range 15-65 pg/mL)
Both are in range.
I was more concerned that despite increases of levothyroxine, and a lowering TSH to the low end of the range, my Free T4 remains at 0% of the range, at the bottom value of the range. Shouldn't my Free T4 be increasing? Why would it not increase with increasing dosage of levo.? Should I be concerned, or should I just focus on the Free T3 levels? What would be the optimum Free T3 level or range?
Thank you for your time.
A good thyroid doctor will treat a hypothyroid patient clinically by testing and adjusting Free T4 and Free T3 as needed to relieve symptoms without being influenced by resulting TSH levels. Symptom relief should be all important, not just test results. I say that about TSH because it is frequently suppressed below range when taking adequate thyroid med. That does not mean hyperthyroidism, unless you have hyper symptoms due to excessive levels of Free T4 and Free T3. Your doctor is erroneously medicating you based on achieving a TSH level to his liking. That does not work for many hypothyroid patients, like yourself. Many of us have found that we needed Free T4 at the middle of the range, at least, and Free T3 in the upper half of the range, adjusted from there as needed to relieve hypo symptoms.
In addition, hypo patients are very frequently deficient in Vitamin D, B12 and ferritin. You need to get those tested and then supplement as needed to optimize. D should be at least 50, B12 in the upper end of the range, and ferritin should be at least 70. All are important of you.
The reason your Free T4 has not increased with increasing med dosage is that serum levels of thyroid hormone are the sum of both natural thyroid hormone and thyroid med. As you start taking thyroid med, TSH drops, and that stimulates less thyroid hormone from the gland. Only when the dosage is increased enough that TSH is no longer a significant factor will further med dosage increases start to increase your Free T4 and Free T3 levels.
If you want to confirm this, read at least the first two pages of this link, and more if you want to get into the discussion and scientific evidence supporting all that is recommended. If your doctor continues to treat you based on TSH you may need to give him a copy and ask to be treated clinically, as described.
Thank you, Gimel, for your response, and link to the pdf. I found the following within that document:
"If the FT4 is below mid-range, then FT3 should be in the upper end of its range, or as needed to assure thyroid
sufficiency (31, 44)."
Note that my FT3 is in the 82% of range on this last test. Most of the treatment recommendation ranges mention FT4 FT3 both in the half or top quarter of the range, but I never see much mention of the FT4 being low and FT3 being high. Since FT3 is the biologically active form of T4, I worry about it being to high. How high is too high for FT3? I don't mind upping my Levothyroxine dose, if I can persuade the endo, but I do worry about too much FT3 as I already have arrhythmia, and increased night sweats.
I expect that the reason your FT3 is higher in range than FT3 is that your body is converting more T4, in an effort to maintain thyroid function as well as possible. So increasing your T4 dosage should not affect FT3 the same amount.
Also, don't be concerned about your TSH. IF you have any reservations about a suppressed TSH, have a look at Rec. 10, on page 13 of the link above.