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Importance of Vitamin D in thyroid health?

I was wondering about the importance of Vitamin D in thyroid health. I noticed that it was the only vitamin my endo asked for in my latest blood tests. Results came in and seems like I'm under the range.
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Avatar universal
Vitamin D is important at the cellular level in the metabolism of Free T3.  The lower range limit for D is not optimal.  D should be at least 50.  

Have you been diagnosed as hypothyroid?  What thyroid related tests have been done and what are the results and reference ranges shown on the lab report?  Even more important, what symptoms do you have?

If you have a look at page 2 of this link you will note that Vitamin D, B12 and ferritin are tests that should be done for hypothyroid patients.   Also, note Rec. 14 on page 14 that lists optimal levels for these.   if you look at Fig. 1 on  page 7 in the link you can note that Vitamin D is shown as a variable affecting Tissue T-3 Effects, which relate to a person's thyroid status.  

Avatar universal
Thank you for the detailed pdf, I'm looking through it and learning a several new things about my condition.

I've been diagnosed as hypo, and today got my most recent lab report. I'm missing the B12 lab though.I also have the saliva cortisol tests results, are those useful?

Main symptoms are fragmented sleep, very poor memory and brain fog, low libido, very low energy in the mornings.

The doctor I'm working with confirmed that I also have low cortisol levels, especially in the morning.

TSH: 0.039
Range: 0.40 - 5.0

Free T4: 1.92
Range: .89 - 1.76

Free T3: 2.99
Range: 2.0 to 4,4

Ferritin: 192.92
Range: 21.8 - 274.66

Vit D: 17
Deficient: 100
Avatar universal
Yes you are terribly low in Vitamin D.  It should be at least 50 ng/mL.

What thyroid med are you taking and what is the daily dosage?
Definitively! I'm already supplementing there.

My current thyroid med is Levo only, 100mcg/day.
Avatar universal
I meant to also say, please post those cortisol results and ranges.

6-8am result: 13
Range: 13-24 nM

11am-1pm result: 7
Range: 5-10 nM

4pm-5pm result: 4
Range: 3-8 nM

10pm result: 4
Range: 1.4 nM

Avatar universal
I was also reported as having 'Depressed DHEA'
Avatar universal
Yes, those cortisol results are too low.  Also, note that it is recommended that any cortisol deficiencies should be corrected before starting on thyroid med.  So you need to find out what your doctor plans to do about your low cortisol.  Note also that when taking med for low cortisol, you also need to get your DHEA to an adequate level, to counteract any bad side effects from the cortisol.  

With your low Vitamin D, you might also ask the doctor about prescribing megadoses for a while to speed up the process.  I don't think you should consider it now, but when you get your cortisol levels adequate, then would be a good time to re-test Free T4 and Free T3, along with Reverse T3 and see if you are still not converting T4 to T3 adequately.  If so, the doctor may need to add a source of T3 to your med.  

When first diagnosed as hypothyroid, what cause was identified: primary (Hashi's), or central?
It was diagnosed when I was a child, probably around 6 years old. I believe I was tested for thyroid antibodies and got negative result, not sure if this means the cause is central.

I'm supplementing a lot with vit d now. About the low cortisol, I need to get a glandular support supplement.

Wouldn't the DHEA levels get better by themselves?
The dr. mentioned that I was converting t4 to t3 well but still need to take t3 to feel normal.
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