is there a way to calculate exact T4 dose for an obese person ?

[Joesmum]

I wonder if obese people need more or less T4 .

Would anyone know how to calculate this?

thank you.

[singlechip]

I am obese (well I lost a lot since on ozempic so I am now in the zone of overweight 😊) While I was on levothyroxine I was taking up to 250 mcg of if. However in my case it didn't work so I had to self medicate with NDT and T3 on which I was feeling better.

[helvella Administrator Thyroid UK]

I don't believe it is ever possible to calculate T4 dose exactly.

We know that when people change makes, or even change from two 50 microgram tablets to one 100 - they can have problems re-establishing a good dose.

We can't assess obesity accurately.

When we get anywhere near a good dose, we have to look at personal, individual responses and blood tests.

I wrote a blog which tries to highlight that all attempts at formulaic dosing have had glaring problems, and contradict each other.

helvella's calculation document and spreadsheet can be can be found by following this link:

helvella - Estimation of Levothyroxine Dosing in Adults

A discussion about the use of formulas to estimate levothyroxine dosing. Includes link to a downloadable spreadsheet which calculates several of these.

helvella.blogspot.com/p/hel...

[Joesmum in reply to helvella]

Hello Helvella,

I’ve just read your article and you make some very interesting points. It all makes very good sense.

If T4 crosses the blood/ brain barrier does that mean that we have a need for T4 prior to conversion?

[helvella Administrator Thyroid UK in reply to Joesmum]

People seem to live amazingly well on T3-only. But T4 definitely crosses the blood brain barrier and is converted within the brain. Indeed, it seems to be converted at controlled different rates across the brain - that is, with incredibly fine management of the process.

I think that we inherently need T4 to allow safe storage and distribution of thyroid hormone - with some conversion being done in various parts such as the liver and distributed round the body, and also locally like in the brain supplying modest areas, and - on top of that- in individual cells like hair follicles where the conversion is strictly for use within that cell.

Add into that fearsome mix, the fact that when well, our thyroids put out a bit of T3.

It's perhaps not surprising that some parts don't get quite enough (whether T4 or T3 or both) even if our overall levels look OK. Hence, many feel the need to have higher levels of thyroid hormones in order to compensate for exogenous thyroid hormone not ever being able to work as well as endogenous.

But that doesn't mean that exogenous T4 is essential in all of us. Just most of us.

[greygoose]

I think the short answer is: no, there isn't. Dosing by weight it just a rough guide, but in the end, you need what you need. And the only safe and certain way to find what you need is to follow the protocol: start low and increase slowly until you reach your 'sweet-spot'.

[Joesmum]

I don’t feel that I’ve ever reached my sweet spot. In all these years with this disease I have never felt well. I’ve battled on ; worked, raised family, continue to work… but my day has always been marred by an insidious lack of well being.

I am now 4 stone overweight. Taking T4 and T3 and still battling to find some degree of wellness. I’m a tough old thing. Like so many of us you’d never know just how bad I feel. I fight on through it and complete the day. Mornings are hell but if I can get out of bed, take the meds and face the day then I do. I want more than anything to feel well. Just for a day. That would do me. My bloods look good on the page. Upper range in both FT’s but I do have very high reverse T3 although I’ve since learnt that this is of no relevance.

My mission for the moment is to get my Ferritin higher. It’s too low. Perhaps it’ll be a lightbulb moment although after all these decades I doubt it.

The hardest thing by far now is my weight. 4 stone over. It’s impacted so many aspects of my life. I have no hunger. The sensation never appears. I lost it 2 years ago exactly. It was the Summer of 2022.

Sorry I feel as though I’m rambling. But this is a rare lucid moment….a brief respite from the brain fog. Sometimes the night times are easier.

[SlowDragon Administrator]

what are your most recent vitamin results

What vitamin supplements are you taking

are you on gluten free and/or dairy free diet

Do you always get same brand levothyroxine

And same brand T3

Do you split your T3 or take as single dose

[Joesmum]

my recent bloods taken last week are -

Serum ferritin level - 83 ug/L. 30.0 - 250.0

Serum folate level - 10.2 ug/L 3.0 -20.5

Serum B12 level - 749 ng/L 200.0 - 900.0

I take - 9000 iu’s Vitamin D3 per day.

100 ug K2.

1000 ug sublingual B12

400 ug folate

20mg Gentle Iron ( iron bisglycinate)

I’ve always used Mercury Pharma T4 and T3 and never accept any other brand. I split my T3 into 2 doses of 10 mcg each

My meds in total are 125 mcg T4 and 20 mcgs T3

I’m not gluten free although I know I should try as I also have Hashimoto's and I do eat and drink dairy.

X

[Jaydee1507 Administrator in reply to Joesmum]

9,000iu vit D is a very high dose. Recommend you test your level as taking too much isnt a good thing.

NHS easy postal kit vitamin D test £31 via

vitamindtest.org.uk

Folate is still on the low side. You could add in a B complex to help balance all your B vitamins.

B complex suggestions: Slightly cheaper options with inactive B6:

amazon.co.uk/Liposomal-Soft...

Contains B6 as P5P an active form:

bigvits.co.uk/thorne-resear...

healf.com/products/basic-b-...

Explanation about the different forms of B6:

helvella.blogspot.com/p/hel...

B complex comparison spreadsheet:

healthunlocked.com/thyroidu...

Ferritin is all but optimal. Optimal said to be 90-100 for best use of thyroid hormone.

Have you done an iron panel recently to check if you still need an iron supplement?

Are your thyroid levels optimised? What are your latest thyroid results?

[Joesmum]

thank you so much for replying.

There is a lot of misinformation around about Vitamin D and dosing. I am fortunate to be under the care of a tremendous endocrinologist who would aim to see Vitamin D levels of 85 to 100 ng/ml . My daily dose of 9000 iu’s keeps me around 75 ng/ml .

You may need to refresh your knowledge regarding Vitamin D. Please don’t use the Vitamin D council as they are years behind current thinking. Lack of absorption is possibly part of my need for higher doses which are perfectly safe. It’s quite necessary to keep levels as optimal as possible and 75 ng/ml is quite respectable.

I shall endeavour to raise my folate and thank you for your advice about the ferritin. I’m pleased that is almost optimal. I shall also add in a B complex although I did try a B 50 Complex last year and it made me horribly anxious so I’ll stick to the lower doses.

My FT’s are both in the upper third of their ranges. TSH is suppressed. I have Central Hypothyroidism, Hashimoto’s and also hypopituitary so a little complicated to treat. My quest to feel well may be futile but one should never give up.

I live in hope !

😊

[Jaydee1507 Administrator in reply to Joesmum]

I was remarking that your vit D dose is high as most members here need 3,000iu to gain an optimal level, although there are some who need 5-6,000iu to get the same result.

So 9,000iu is a lot more than the majority of members need. Genes have a role to play in some people requiring more.