T4 levels in relation to T3 dose

[Popscicle]

can anyone tell me - is it normal to have a T4 at the low end of the range once you start taking Liothyronine T3.? I take 125mcg thyroxine and 10mcg Liothyronine 3x a day. My T3 comes back mid range and T4 at the bottom of the range whilst TSH is v v suppressed (0.01). I’m sorry but I will need to get the exact results from the hospital. My brain fog has cleared with T3 but I’m still v tired all the time. I’m thinking of going back to endo for advice but I really want to know about it he effect of oral T3 on blood levels of T4 first. I have monthly IV iron, daily 2 forms of vit d (with K2M) & folic acid 5 mg daily (because I also Hv a renal condition).. so I know my nutrient levels are high (B12 was at the top of the range when tested last month).

thanks for any help anyone can give.

[TiggerMe Ambassador]

Welcome aboard

It's not unusual for fT4 levels to drop when starting T3 and if your level was already less than 70% or you we told to reduce your T4 by too much when starting this can make you feel pretty grim after a few weeks. Many Endo's seem to cut T4 rather too much regardless of your levels 😬

Do you really mean 3 x 10mcg T3 as your starting dose or 10mcg split into 3 doses?

30mcg a day would be a lot to start on!

Ideally keeping your fT4 around 50-70% seems to work for many when also taking T3 but you'll need to work out your own sweet spot by trial and error

[Popscicle in reply to TiggerMe]

Hi Eeyore - yes I am new to posting altho I’ve been a member for 14m now. I wrote a previous reply to you but at the moment I can’t see it on here. Maybe I did something wrong but Thanku so much for your help.

[TiggerMe Ambassador in reply to Popscicle]

I thought you sounded familiar but I couldn't find any history either? 🙃

[Popscicle in reply to TiggerMe]

I’ve completed my ‘personal information’ bit and my story and I see it when I press on my face icon so I’ve no idea why you can’t see it. Mind you, it’s taken me ages to work out how to post so I may Hv made a mistake somewhere!

[TiggerMe Ambassador in reply to Popscicle]

Well done, I can see your Bio but no previous posts?

[helvella Administrator in reply to TiggerMe]

There are 26 replies - but no new posts.

healthunlocked.com/user/Pop...

[Popscicle in reply to helvella]

It’s the first time I’ve posted because I couldn’t work out how to do it! Then I’ve been away so was delayed in responding to everyone’s comments. I apologise. It’s strange because replies Hv only come up in my email today. I’m so sorry for my slow response!

[TiggerMe Ambassador in reply to helvella]

Thanks 🍄... it's a right old jumble isn't it 😵

[Popscicle in reply to TiggerMe]

In my reply to Helvetia you can see the explanation as to why there are no previous posts (I couldn’t work out how to do it)! I also got stuck on the bit that wants you other comorbities, & your medication etc. I’d enter stuff and it seemed to churn it up and not record it! I think I’m relatively intelligent but always get stuck with techy stuff like Instagram etc. I can’t seem to work out how to do things like messaging! I admit I’m a bit of an over thinker! Mind you I’m good with FB!

[Lalatoot]

When I was on 100mcg levo alone my ft4 sat at 60% through range and my ft3 at 17%.Now I am on 100mcg levo and 7.5mcg liothyronine t3, my ft4 sits at 50% and my ft3 at 72%.

It would seem that adding a small amount of liothyronine has reduced my ft4 by 10%.

[Popscicle in reply to Lalatoot]

thanks lalatoot - I did send a previous reply but can’t see it here so maybe I didn’t d something wrong. But thanks for ur help, that’s reassuring.

[waveylines in reply to Popscicle]

It's probably happened because adding the small amount of T3 in has supported your body to utilise and convert so your metabolism has increased. I would take this as a good sign and it maybe that next time your Endo will increase your levothyroxine.How do you feel?

[Popscicle in reply to waveylines]

So sorry for delayed reply. Soon after starting T3 my brain became sharp again, I could concentrate for hours and all my ‘cloudy’ symptoms went. However I still feel tired, at times I feel a bit unsteady on my feet and I’ve lost 7kg which I put down to the T3. I didn’t Hv any weight to lose and at diagnosis in 2016 I was 48kg so I didn’t experience the weight gain that is typical of hypothyroidism. I think my hypothyroidism is due to some sort of hypothalamic dysfuntion. However I also Hv a renal disease which could explain my remaining symptoms. Over all I do feel a lot better taking T3 so I’m not desperate to change anything. I’m going to wait for 2 more sets of bloods (8w apart) to see if the pattern of low ish T4 changes. Many thanks for your help.

[Popscicle in reply to Lalatoot]

Thankyou that’s helpful. When I saw the endo in March ‘22, he started Liothyronine at 10mcg three x a day or 30mcg a day! I had cottoned on to the fact that he didn’t seem to know what he was talking about but didn’t realise it was a massive dose to start on. I only learned that here! After a few days of feeling jittery I settled and Hv had improved symptoms. However I lost 7kg in weight between then and Christmas and I didn’t Hv weight to lose. I haven’t managed to put it back on yet. I’m so sorry for my delayed reply, I’ve been away.

[Beads]

Morning.

Random non-thyroid question regarding the folate and kidney.

Is there a connection? Does low kidney function relate to lower folate levels, or do higher folate levels protect/help the kidney in some way?

Yes, probably better off asking in the kidney forum, but they’re very American over there, it’s much less busy than here, and they seem to focus on very low gfr. And I like here better.

[beh1 in reply to Beads]

Hi Beads

You’re more likely to get replies if you start a new thread rather than adding to this one, as people may not notice your query.

[Popscicle in reply to Beads]

Hi Beads, I’m sorry for my delayed reply. If the gfr is low, levels of B12 and folate will drop. This is largely due to reduced reabsorption in the tubes in the kidney ( so the vitamins are lost in urine).

Low levels of both B12 and folate disturb homocysteine metabolism leading to high homocysteine levels (homocysteine is a waste product of methionine metabolism but basically just think of it as a toxic substance).

Without adequate B12 and folate, homocysteine can’t be metabolised leading to high levels. High levels cause kidney function to deteriated ie CKD (chronic kidney disease) to accelerate.

It also accelerates CVD (cardiovascular disease). So in summary;

People with CKD often have low folate and B12 levels due to a low gfr impairing their reabsorption in the kidney tubules.

These vitamins are needed in the body to get rid of a toxic substance (homocysteine) and low vitamin levels will lead to a rise in that toxic substance.

That substance accelerates CKD (therefore further worsening levels of B12 and folate). The toxic substance also accelerates CVD.

So ideally, all patients with CKD should supplement B12 and folate. And have regular blood tests. You can’t overdose because both are water soluble and any xs will be excreted into urine by the kidneys. Furthermore, the kidneys and the liver Hv B12 storage areas which can store B12 for up to 3 years.