T4 to T3 conversion: Does T4 to T3 conversion... - Thyroid UK

Thyroid UK

140,263 members164,956 posts

T4 to T3 conversion

Jingley profile image
16 Replies

Does T4 to T3 conversion lessen with age? I'm just trying to figure out why I feel 20 years older than my real age.

No changes to any meds and supplements and TSH and T4 levels are on a par with where they've been for several years. Ferritin is low but I suspect it's been that way for a long time.

I know I'm getting older but when you do a supermarket shop in a morning then are wiped out for the rest of the day, something's changed.

Written by
Jingley profile image
Jingley
To view profiles and participate in discussions please or .
Read more about...
16 Replies
SlowDragon profile image
SlowDragonAdministrator

For good conversion of Ft4 (levothyroxine ) to Ft3 (active hormone) it’s important to maintain GOOD vitamin levels

Please add most recent vitamin D, folate, B12 and ferritin results and ranges

If you have low ferritin this can cause exhaustion

GP should be doing full iron panel including ferritin

Conversion often gets worse post menopause as well

Do you always get same brand levothyroxine at each prescription

How much are you taking

Please add most recent TSH, Ft4 and Ft3 results

Jingley profile image
Jingley in reply to SlowDragon

Please add most recent vitamin D, folate, B12 and ferritin results and ranges

Vitamin D -- 106 (50-250)

Vitamin B12 -- 536 (211-911)

Folate -- 18.3 (>5.4)

Ferritin -- 19 (15-200)

If you have low ferritin this can cause exhaustion

GP should be doing full iron panel including ferritin

Ferritin is within range so fine - GP's words

Trying a DIY approach with supplements

Conversion often gets worse post menopause as well

Do you always get same brand levothyroxine at each prescription

Yes. Always Accord but considering requesting Vencamil as lactose and fructose intolerant

How much are you taking

100mcg daily

Please add most recent TSH, Ft4 and Ft3 results

TSH 0.08 mIU/L (.27 - 4.2) -4.8%

Free T4 (fT4) 21.1 pmol/L (12 - 22) 91.0%

Free T3 (fT3) 4 pmol/L (3.1 - 6.8) 24.3%

SlowDragon profile image
SlowDragonAdministrator in reply to Jingley

Ferritin is within range so fine - GP's words

Obviously that’s rubbish

Low ferritin tends to lower TSH because poor conversion leads to higher Ft4 and lower Ft3

High Ft4 results in lower TSH

Anaemia

cks.nice.org.uk/topics/anae...

"Anaemia is defined as a haemoglobin (Hb) level two standard deviations below the normal for age and sex.

In men aged over 15 years — Hb below 130 g/L.

In non-pregnant women aged over 15 years — Hb below 120 g/L.

In children aged 12–14 years — Hb below 120 g/L.

In pregnant women — Hb below 110 g/L throughout pregnancy. An Hb level of 110 g/L or more appears adequate in the first trimester, and a level of 105 g/L appears adequate in the second and third trimesters.

Postpartum — below 100 g/L."

diagnosis is confirmed (following the Hb result) by a ferritin<30.

Serum ferritin level is the biochemical test, which most reliably correlates with relative total body iron stores. In all people, a serum ferritin level of less than 30 micrograms/L confirms the diagnosis of iron deficiency

The reason is says "in all people" is because the hb levels are differentiated for sex and pregnancy status, but ferritin is not.

NHS follows Nice guidance, The cks are from NICE, and NICE guides NHS practice.

Serum ferritin level is the biochemical test, which most reliably correlates with relative total body iron stores. In all people, a serum ferritin level of less than 30 micrograms/L confirms the diagnosis of iron deficiency

Never supplement iron without doing full iron panel test for anaemia first and retest 3-4 times a year if self supplementing.

It’s possible to have low ferritin but high iron

Test early morning, only water to drink between waking and test. Avoid high iron rich dinner night before test

If taking any iron supplements stop 5-7 days before testing

Medichecks iron panel test

medichecks.com/products/iro...

Look at increasing iron rich foods in diet

Eating iron rich foods like liver or liver pate once a week plus other red meat, pumpkin seeds and dark chocolate, plus daily orange juice or other vitamin C rich drink can help improve iron absorption

List of iron rich foods

dailyiron.net

Links about iron and ferritin

irondisorders.org/too-littl...

davidg170.sg-host.com/wp-co...

Great in-depth article on low ferritin

oatext.com/iron-deficiency-...

drhedberg.com/ferritin-hypo...

This’s is interesting because I have noticed that many patients with Hashimoto’s disease and hypothyroidism, start to feel worse when their ferritin drops below 80 and usually there is hair loss when it drops below 50.

healthunlocked.com/thyroidu...

Posts discussing Three Arrows as very effective supplement

Great replies from @FallingInReverse

re ferritin and Three arrows

healthunlocked.com/thyroidu......

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

Great reply by @fallinginreverse

healthunlocked.com/thyroidu...

Iron patches

healthunlocked.com/thyroidu...

Thyroid disease is as much about optimising vitamins as thyroid hormones

healthunlocked.com/thyroidu...

restartmed.com/hypothyroidi...

Post discussing just how long it can take to raise low ferritin

healthunlocked.com/thyroidu...

Iron and thyroid link

healthunlocked.com/thyroidu...

Posts discussing why important to do full iron panel test

healthunlocked.com/thyroidu...

Good iron but low ferritin

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

Chicken livers if iron is good, but ferritin low

healthunlocked.com/thyroidu...

Shellfish and Mussels are excellent source of iron

healthline.com/nutrition/he...

Iron deficiency without anaemia

healthunlocked.com/thyroidu...

Ferritin over 100 to alleviate symptoms

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

Great research article discussing similar…..ferritin over 100 often necessary

ncbi.nlm.nih.gov/pmc/articl...

Low Iron implicated in hypothyroidism

healthunlocked.com/thyroidu...

Really interesting talk on YouTube, link in reply by Humanbean discussing both iron deficiency and towards end how inflammation can also be an issue

healthunlocked.com/thyroidu...

Inflammation affecting ferritin

healthunlocked.com/thyroidu...

Updated reference ranges for top of ferritin range depending upon age

healthunlocked.com/thyroidu...

Thank you for your incredible patience while you have been awaiting the outcome of our ferritin reference range review. We conducted this with Inuvi lab, which has now changed the reference ranges to the following:

Females 18 ≤ age < 40. 30 to 180

Females 40 ≤ age < 50. 30 to 207

Females 50 ≤ age < 60. 30 to 264l

Females Age ≥ 60. 30 to 332

Males 18 ≤ age < 40 30 to 442

Males Age ≥ 40 30 to 518

The lower limits of 30 are by the NICE threshold of <30 for iron deficiency. Our review of Medichecks data has determined the upper limits. This retrospective study used a large dataset of blood test results from 25,425 healthy participants aged 18 to 97 over seven years. This is the most extensive study on ferritin reference ranges, and we hope to achieve journal publication so that these ranges can be applied more widely.

DippyDame profile image
DippyDame

Age can play a part but the main problem is your thyroid hormone levels

Your conversion rate may have declined for various reasons, which has resulted in very low FT3 and high FT4

100mcg T4 is not a vastly high dose but you would benefit from the introduction of T3....this also naturally reduces T4.

High FT4 is best avoided as it has the potential to cause problems.

For good health every cell in the body must be flooded with T3 by way of an adequate and constant supply.

The T3 must reach the nuclei of the cells , attach to T3 receptors there and so become active before it can fulfill it's function

At 24.3% through the reference range that isn't happening and you are consequently experiencing symptoms of hypothyroidism.

You need more T3⁹

Optimal nutrients, vit D, vit B12, folate and ferritin are essential to support thyroid function

We aim to have both Frees roughly approaching 75% though their respective reference ranges.

Suggest you see an endo with a view to having a trial of T3.....they prefer trial requests to requests for T3!!

Jingley profile image
Jingley in reply to DippyDame

Since diagnosis and Levo replacement I've always felt ok-ish but never back on top form which leads me to suspect that I've had issues converting T4 to T3 all along.

My GP, although generally a good doctor who listens, is very TSH focused and refused my request for referral to Endo.

I think I'm going to have to self refer to a private Endo.

I really can't go on like this. I feel like I'm existing not living.

TiggerMe profile image
TiggerMe in reply to Jingley

You could save yourself the £££ and hassle of finding a decent Endo as you already know what you need.... I'd suggest having a consultation with rosewaylabs.com/patients/ who will monitor and can also supply... word is they are excellent and considerably cheaper than an Endo 😏

FancyPants54 profile image
FancyPants54 in reply to TiggerMe

They are excellent. I use them. Great service.

Judithdalston profile image
Judithdalston in reply to FancyPants54

so do I, Roseway Labs very good , much cheaper…only disadvantage is I let slip their prescriber is a GP and not an endo ( not that makes much difference we know), but he said that was not good enough and he needed a specialist to advise on thyroid hormone dosing. I had had one, privately, and letter on my notes about dosing etc but it gets expensive to keep them on the books just to say ‘ok’ to my own privately funded blood tests, and to get a private prescription out of him every 3 months or so. I refused to go back to him, so for the very first time , in 25 years, he has referred me out of Trust to an NHS endo.

DippyDame profile image
DippyDame in reply to Jingley

I don't know why doctors are so clueless about thyroid disease....and as for TSH mania....

Good advice from TM re Roseway labs.

I self medicate with T3-only....hit a brick wall with medics!

Yes I suspect your conversion may have gradually deteriorated over time with cellular T3 level falling.

Good luck, we're all here to help.....just ask!

FancyPants54 profile image
FancyPants54 in reply to Jingley

I second the suggestion to use Roseway Labs. Their prescribing pharmacist is so good and kind.

McPammy profile image
McPammy

I’d been taking levothyroxine only for years then suddenly when I was 59 I hit a wall so to speak. I was never great just on levothyroxine but I use to muddle along. At 59 suddenly my energy levels plummeted. My gp increased my levothyroxine even though it was already at the top of its range. I went over medicated and ended up collapsing and into hospital. There they did a t3 test. First ever in my life. My t3 was only 8%. NHS still refused t3 trial criminally in my mind. I could barely walk for months. I went private after being advised on here. I was given t3 medication immediately. Oh my goodness what a change that made. Suddenly and I mean within 2/3 days I could walk normally and had lots of energy and strength. I’ve read a few articles about metabolic rate after 60. It nose dives from 60 onwards gradually. I believe I could struggle on in my 50’s but at 59 onwards naturally my metabolic rate declined. I am a poor converter of t4 to the magic t3 hormone so I did need the help of the addition of T3 liothyronine

I do believe t4 to t3 can lessen with age and 60ish is the gradual point it starts. But people also have a conversion issue on top too. I did the DIO2 test also which came back positive.

Today I’m symptom free as I keep my TSH just about in range therefore levels in range also. I’ve been symptom free since starting t3 5 years ago now. Prior for over a decade I had lots of symptoms just in levothyroxine t4. I also now have liquid levothyroxine which I think helps too.

Jingley profile image
Jingley in reply to McPammy

Muddling along. That's me exactly. I really think I'm going to have to cut my GP out of things and start to take back some control of my wellbeing.

My GP, although very good at listening and will follow through with tests (diagnosed me with lactose intolerance by symptoms before test results came back and admitted that some diagnoses are catch-all bucket type things) still insists that I can't possibly still be hypo as my TSH says I'm not. My symptoms are down to other things but can't find out just what they are!

I have bought Paul Robinson's Thyroid Patients Manual and will read it cover to cover.

Just nervous about going my own way in case things go wrong 😨

DippyDame profile image
DippyDame in reply to Jingley

Your GP needs to move out of the misleading TSH groove! He is wrong!

T3 is key!

We're all here to help....just ask

McPammy profile image
McPammy in reply to Jingley

Things shouldn’t get any worse than a gp recommendation. Focus on getting g your vitamins really good and keeping them there with regular blood tests. Eat as healthy as you can and exercise even if that’s brisk walks daily. I do these things and for myself I keep my TSH and t4. T3 levels in range just like a healthy persons would be.

Jingley profile image
Jingley

A huge thank you to SlowDragon DippyDame TiggerMe FancyPants54 McPammy

I'll be doing a lot of research over the next few days and may just have the need of a little hand holding 🫂❤️

ainslie profile image
ainslie

have you considered it might be your short in other hormones as they tend to lower as we age

Not what you're looking for?

You may also like...

T3 to T4 Conversion Issues

Hello everyone, I posted this on another thread and was advised to create my own post (I think I...

T4 to T3 conversion issue

Two months ago I have been finally prescribe T3 privately What a difference it has made to me. For...

T4 to T3 conversion problem?

Hello all. I wanted to ask for interpretations of my recent thyroid lab results. With some context,...

NDT to T4 plus T3 conversion

Evening all, I hope you're all managing to stay safe, well and sane during these trying times! I...

T4 to T3 conversion

Hi everyone, I’m in a bit of a wrangle. I’m on T3 only. I’m a graves and have had RAI about 10...