Question:
Hello Doctor!

These 2 questions are on behalf of my niece who was diagnosed with Hashimoto’s Thyroiditis in 2018. I wanted to add that when I first found out about the diagnosis, I started taking low doses of iodine and selenium, and that helped to increase my FT4 and reduce my thyroid antibodies. I am still taking these supplements.
Also, I am now pregnant.

Here are my 2 questions:
(1) Could you please explain why my TSH has always been in the normal range, despite low ft3 and ft4? This was even the case before my pregnancy.

(2) Is ft3 more important than ft4, since most of the t4 gets converted to t3? Before I started medication my ft3 was always lower than the limit, despite having a normal ft4. If I don't have a conversion problem, could you please explain why the t4 is not getting converted to t3?

History:
Since the time of diagnosis, my TSH has stayed normal (between 1 and 2 mU/l) despite my FT3 and FT4 levels being below the limits. I didn’t have any symptoms and didn’t take any medication, and managed to get my FT4 into the reference range through diet and supplementation. However, my FT3 remained below the reference range.
 
In August 2020, I started taking Natural Dessicated Thyroid extract, which is a combination of T3 and T4. I did not take L-thyroxine, as it is purely T4 supplement, and it was pointed out to me that I have a T4 to T3 conversion problem, not a T4 problem, as my FT4 was in the normal range. I also found out that I became pregnant in August.
I have increased my dosage twice since the start of the pregnancy. My results from the past few months, along with the reference ranges, are listed below:


Reference values:
 
TSH: 0.5-4 mU/l
FT3: 2.3 – 4.1 ng/l
FT4: 9 - 17 ng/L
 
Test results:
 
Date: 14.10.20
TSH = 0.61 mU/l
FT3 = 3.3 ng/l
FT4 = 12.4 ng/l
 
Date: 17.12.20
TSH = 0.63 mU/l
FT3 = 2.56 ng/l
FT4 = 8.5 ng/l
 
After finding out that my FT4 was below the reference range, I increased my NDT dosage from 3⁄4 grain to 1 grain on December 26th, 2020
 
Date: 14.01.21
TSH = 0.66 mU/l
FT3 = 3.26 ng/l
FT4 = 7.9 ng/l
 
I wanted to add that when I first found out about the diagnosis (Hashimoto's thyroiditis), I started taking low doses of iodine and selenium and that helped to increase my FT4 and reduce my thyroid antibodies. I am still taking these supplements.

Hello Doctor!

These 2 questions are on behalf of my niece who was diagnosed with Hashimoto’s Thyroiditis in 2018. I wanted to add that when I first found out about the diagnosis, I started taking low doses of iodine and selenium, and that helped to increase my FT4 and reduce my thyroid antibodies. I am still taking these supplements.
Also, I am now pregnant.

Here are my 2 questions:
(1) Could you please explain why my TSH has always been in the normal range, despite low ft3 and ft4? This was even the case before my pregnancy.

(2) Is ft3 more important than ft4, since most of the t4 gets converted to t3? Before I started medication my ft3 was always lower than the limit, despite having a normal ft4. If I don't have a conversion problem, could you please explain why the t4 is not getting converted to t3?

History:
Since the time of diagnosis, my TSH has stayed normal (between 1 and 2 mU/l) despite my FT3 and FT4 levels being below the limits. I didn’t have any symptoms and didn’t take any medication, and managed to get my FT4 into the reference range through diet and supplementation. However, my FT3 remained below the reference range.
 
In August 2020, I started taking Natural Dessicated Thyroid extract, which is a combination of T3 and T4. I did not take L-thyroxine, as it is purely T4 supplement, and it was pointed out to me that I have a T4 to T3 conversion problem, not a T4 problem, as my FT4 was in the normal range. I also found out that I became pregnant in August.
I have increased my dosage twice since the start of the pregnancy. My results from the past few months, along with the reference ranges, are listed below:


Reference values:
 
TSH: 0.5-4 mU/l
FT3: 2.3 – 4.1 ng/l
FT4: 9 - 17 ng/L
 
Test results:
 
Date: 14.10.20
TSH = 0.61 mU/l
FT3 = 3.3 ng/l
FT4 = 12.4 ng/l
 
Date: 17.12.20
TSH = 0.63 mU/l
FT3 = 2.56 ng/l
FT4 = 8.5 ng/l
 
After finding out that my FT4 was below the reference range, I increased my NDT dosage from 3⁄4 grain to 1 grain on December 26th, 2020
 
Date: 14.01.21
TSH = 0.66 mU/l
FT3 = 3.26 ng/l
FT4 = 7.9 ng/l
 
I wanted to add that when I first found out about the diagnosis (Hashimoto's thyroiditis), I started taking low doses of iodine and selenium and that helped to increase my FT4 and reduce my thyroid antibodies. I am still taking these supplements.

Thanks Dr. Biswas! I have two more questions related to my condition:
(1) Is it dangerous to the fetus if my FT4 levels remain low, or should I increase my dosage again?
(2) Are there any other protocols that you would recommend that I follow in order to increase my thyroid hormone production?
Thanks in advance.

Thanks Dr. Biswas! I have two more questions related to my condition:
(1) Is it dangerous to the fetus if my FT4 levels remain low, or should I increase my dosage again?
(2) Are there any other protocols that you would recommend that I follow in order to increase my thyroid hormone production?
Thanks in advance.