Thyroid Blood test results - high reverse T3

[Colours27]

Following on from my initial post here - healthunlocked.com/thyroidu...

I got a full thyroid check from Blue Horizon, results below.

I havent changed medication up to 100mg Levothyroxine as not been able to register at surgery in the town i moved to yet, but will be doing that very soon.

My TSH has remained constant with last blood test about 4 months ago , but as noted previously is still high.

Vitamin D deficiency probably makes sense as i work indoors a lot and dont spend as much time outside as i should - although trying to more and more. Does this impact thyroid much?

Im not that knowledgeable on Reverse T3, what does this indicate?

I came across this article - invivoclinical.co.uk/invivo...

It mentions reverse T3 can be high due to starvation and extreme carbohydrate restriction - i have been doing a pretty consistent time restricted feeding routine for the past 8 months or so, usually not eating for a period of 14 hours per day (so keeping all my food intake within 10 hours - usually 9am to 7pm) and have been cutting down my carb in take a lot, as trying to heal my gut and lose weight by countering my slowed metabolism due to thyroid - could that be the cause of the Reverse T3 or unlikely to affect that much?

Further note - The blood test was a fasting one and i had fasted for about 16-17 hours by the time the blood was drawn so this also may have contributed.

Thanks in advance for any comments!

Biochemistry

HbA1c-(IFCC) 33 /// 20 - 42 mmol/mol

hs-CRP 0.53 /// <5.0 mg/L

Ferritin 184.0 /// 30 - 400 ug/L

Magnesium 0.98 /// 0.66 - 1.07 mmol/L

Hormones

Insulin 52.0 /// <173(Fasting) pmol/L

Thyroid Function

TSH H 4.97 /// 0.27 - 4.20 mIU/L

T4 Total 92.5 /// 66 - 181 nmol/L

Free T4 18.40 /// 12.0 - 22.0 pmol/L

Free T3 4.63 /// 3.1 - 6.8 pmol/L

Reverse T3* H 26.0 /// 10 - 24 ng/dL

Reverse T3 ratio L 11.59 /// Normal >15 Ratio Borderline 12-15 Low <12

Immunology

Anti-Thyroidperoxidase abs <9.0 /// <34 kIU/L

Anti-Thyroglobulin Abs <10 /// <115 kU/L

Vitamins

Vitamin D (25 OH) L 36 /// Deficient <30 nmol/L Insufficient 30 - 50 Consider reducing dose >175

Vitamin B12 433 /// Deficient <145 pmol/L Insufficient 145 - 250 Consider reducing dose >569

Serum Folate 24.20 /// 8.83 - 60.8 nmol/L

[shaws Administrator]

Levothyroxine is T4 - T4 converts to RT3 and then into T3. I am not medically qualified but this is an explanation about RT3 from a doctor who was an Adviser to TUK before his death.

"This is from Dr. Lowe:

"Dr. Lowe: Some readers will not be familiar with reverse-T3, and I know from experience that many others harbor misconceptions about the molecule. Because of this, I have summarized in the box below what we know about reverse-T3. I've answered your question below the summary.

Conversion of T4 to T3 and Reverse-T3: A Summary

The thyroid gland secretes mostly T4 and very little T3. Most of the T3 that drives cell metabolism is produced by action of the enzyme named 5'-deiodinase, which converts T4 to T3. (We pronounce the "5'-" as "five-prime.")

Without this conversion of T4 to T3, cells have too little T3 to maintain normal metabolism; metabolism then slows down. T3, therefore, is the metabolically active thyroid hormone. For the most part, T4 is metabolically inactive. T4 "drives" metabolism only after the deiodinase enzyme converts it to T3.

Another enzyme called 5-deiodinase continually converts some T4 to reverse-T3. Reverse-T3 does not stimulate metabolism. It is produced as a way to help clear some T4 from the body.

Under normal conditions, cells continually convert about 40% of T4 to T3. They convert about 60% of T4 to reverse-T3. Hour-by-hour, conversion of T4 continues with slight shifts in the percentage of T4 converted to T3 and reverse-T3. Under normal conditions, the body eliminates reverse-T3 rapidly. Other enzymes quickly convert reverse-T3 to T2 and T2 to T1, and the body eliminates these molecules within roughly 24-hours. (The process of deiodination in the body is a bit more complicated than I can explain in this short summary.) The point is that the process of deiodination is dynamic and constantly changing, depending on the body's needs."

and

toopoopedtoparticipate.com/...

[Colours27 in reply to shaws]

Thanks shaw, i think that sheds some light, so effectively not that useful in determining much here, especially under the conditions in which blood was drawn after a 16-17 hour fast (and probably my anxiety and therefore cortisol levels high due to apprehension of blood test!)

[shaws Administrator in reply to Colours27]

Others will respond re your other results of vitamins/minerals. Everything has to be optimal.

However, your TSH is FAR too high, the aim is 1 or lower. You need an increase in dose but so many doctors think that if TSH is 'in range' we're on sufficient dose. But you aren't yet on an optimum.

healthunlocked.com/thyroidu...

[Colours27 in reply to shaws]

Thankyou shaws, that is my plan!