Dosing levels : Is it possible to tell by the... - Thyroid UK

Thyroid UK

141,188 members166,426 posts

Dosing levels

HowNowWhatNow profile image
18 Replies

Is it possible to tell by the ratio of levo & lio dosing levels to the person’s height:weight alone (assuming the person’s TSH numbers have come back to euthyroid or less than euthyroid) whether that person is a good converter?

I am on 150 mcg of levo and half a tablet of Thybon Henning a day and my BMI is 20/21, as it’s always mean.

I have got an extremely sluggish digestion system and very poor circulation. My weight has not changed since being on thyroid medication, but my digestion and circulation have both got worse and slower. I don’t know what this says about thyroid medications and metabolism.

I don’t have my thyroid numbers to hand but this, today, is not a question about whether my thyroid numbers are in the right zone, it’s about height:weight and its relevance to thyroid medicine dosing and how we know using these numbers alone whether we are converting well, and know whether to get the genetic test.

thanks!

Written by
HowNowWhatNow profile image
HowNowWhatNow
To view profiles and participate in discussions please or .
Read more about...
18 Replies
Jaydee1507 profile image
Jaydee1507Administrator

As far as I am aware the only way to tell if you're converting or not is to be on Levo only. Once you're on combination therapy its no longer possible to tell anything.

If you're already on t4/t3 then why would you need to know if you have a genetic issue with conversion?

Poor circulation may also be related to other factors such as faulty collagen as seen in Ehlers Danlos Syndrome.

For sluggish digestion I found a low carb diet helped me.

HowNowWhatNow profile image
HowNowWhatNow in reply toJaydee1507

hi

I was on levo only for 6 or 7 years so could look back at my numbers from then.

I could have my liothyronine dose increased, and levo decreased if poor converter, if poor converter.

These symptoms are part of the main reason why I was put on these drugs and appeared at the same time as my thyroid numbers changed, which is a big part of why I bundle them together and ask the question. As well as optimism that I can improve my health, through research.

HowNowWhatNow profile image
HowNowWhatNow in reply toJaydee1507

thank you.

SlowDragon profile image
SlowDragonAdministrator

Have you ever split your T3 as 2 x 5mcg

Always split T3 day before test, with last 5mcg dose 8-12 hours before test

Always get same brand levothyroxine at each prescription?

Essential to maintain OPTIMAL Vitamin levels

When were vitamin D, folate, ferritin and B12 last tested

Are you gluten free/dairy free

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

I’ve never tried splitting the dose, no. I will try.

I have deferred taking meds the day before tests, though.

Re: vitamins

When last tested, these have all been OK with one exception.

My ferritin level is too low (11 when last tested - when 13 is at the bottom of the healthy range) and my body doesn’t agree with me taking iron supplements - not even Sytron - but the NHS is taking forever to get me an iron infusion, so I’m limping along until it does. I’ve recently discovered that I have some kind of pelvic prolapse - quite possibly caused by taking iron supplements - that means I have another reason to not take any more iron supplements.

Vicious circles.

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

I am not dairy free.

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

Thanks for your help.

I haven’t had folate, Vit D or B12 tested for a year or so.

SlowDragon profile image
SlowDragonAdministrator in reply toHowNowWhatNow

Get these tested

No thyroid hormones can work well unless all four vitamins are optimal

Vitamin D at least over 80nmol

Serum B12 over 500

Active B12 over 70

Folate and ferritin at least half way through range

Ferritin

Good explanations of iron 

theironclinic.com/iron-defi...

theironclinic.com/ironc/wp/...

Helpful info on iron infusion and supplements 

healthunlocked.com/thyroidu...

Excellent reply by Blearyeyed about iron in this post

healthunlocked.com/thyroidu...

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

thank you

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

And to go back to the root of my question - is 150 mcg and a half pill of T3 per day in someone weighing 62 kg a normal dosing level?

Separate from vitamin levels.

There have been times in the last few years when all my vitamin levels have been normal, but I’ve still had circulation and digestion problems. So vitamins haven’t been the major factor up until now.

SlowDragon profile image
SlowDragonAdministrator in reply toHowNowWhatNow

There have been times in the last few years when all my vitamin levels have been normal,

Normal…..or optimal?

Malabsorption common issue due to wide variety of causes

Low stomach acid

SIBO

H Pylori

Gluten intolerance

Dairy intolerance

etc

More listed here

hypothyroidmom.com/hashimot...

Malabsorption discussed in detail here

academic.oup.com/edrv/artic...

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

Yes, I have had SIBO v recently and have had H Pylori almost two years ago. I took antibiotics for them both times.

Both of those things appeared after a) repeatedly taking iron supplements for an iron deficiency and b) sluggish digestion since having a thyroid condition, both of which in turn caused constipation and in turn caused pelvic prolapse, which then created more bowel / colon problems. The fun doesn’t stop.

I am also on Nifedipine for poor circulation, which still isn’t fixing the problem.

Since taking antibiotics for SIBO and going on a low Fodmap diet for 8 weeks then too, I have been much more restrictive about my diet. It hasn’t cured the problems I describe, sadly.

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

The only vitamin I am consistently low for is ferritin.

I have two children who are constantly ill with different things needing my attention, and have pretty poor memory (along with the poor circulation and digestion) and have a few other health problems I haven’t described here so I follow a “good enough” approach to vitamins as with most things.

I don’t focus on whether my vitamin levels are perfect - I know I am not robust enough to chase down all health routes at once - I can only focus on iron, which is taking up enough time as it is!

Props to anyone who has secured iron infusions through the NHS. Should be so easy but is harder to do than getting that camel though the eye of a needle.

SlowDragon profile image
SlowDragonAdministrator in reply toHowNowWhatNow

Private iron infusion about £400 I believe

Get vitamin D, folate and B12 tested

Many (most?) on levothyroxine need to supplement vitamin D and vitamin B complex continuously to maintain optimal levels

Approximately 86% Hashimoto’s patients benefit from strictly gluten free diet

And about 60% benefit from dairy free

HowNowWhatNow profile image
HowNowWhatNow in reply toSlowDragon

thank you.

Last time I investigated the iron infusion cost it was more like £7-800. At the Iron Clinic in London it’s £770.

While it won’t bankrupt us to pay for this equally we have many other things I need to spend money on and buy. All of which cost more than they did last year.

PS. How can they call a trial into Heart Failure in all patients low in iron “Iron Man”?

Things I don’t understand Part 3246788445

bhf.org.uk/what-we-do/news-...

greygoose profile image
greygoose

it’s about height:weight and its relevance to thyroid medicine dosing and how we know using these numbers alone whether we are converting well, and know whether to get the genetic test.

I don't think height has anything to do with dosing or conversion. There are certain recommendations for dosing by weight, but that's only a rough ball-park estimation, usually used for people who have just had their thyroids removed, as a starting dose. It has little referrence to other forms of hypo. And certainly nothing to do with conversion. So, no, your height-weight ration can in no way tell you how well you convert, there is no connection.

There can be many, many reasons why people have poor conversion, and not always possible to do anything about it. And the best way to tell how well you convert is to compare your FT4 to your FT3 when on levo mono-therapy, with a TSH around 1. The genetic test will only tell you if you are likely to be a poor converter, not if you are. Hope that answers your question. :)

HowNowWhatNow profile image
HowNowWhatNow in reply togreygoose

Can you please explain how or why dosing recommendations for thyroid conditions won’t have any correlation to or starting point from height and weight, ie. BMI?

My GP and thyroid specialist have both said I am on a high dose for my size & shape.

How do doctors start children off on thyroid medicine, if not going from their height and weight?

What I am asking is whether it can help people - on a very basic level, not in detail - know whether they are a bad converter. Perhaps you will think this is the same thing.

There must be some research out there that looks at sizing doses and plots it against patients’ weight and height. Even if it concludes by saying that the relationship is random / skewed by XYZ, I’d love to see it.

greygoose profile image
greygoose in reply toHowNowWhatNow

I have never heard of such research, no. That doesn't mean it hasn't been done, of course, but if it has, I don't know anything about it.

BMI is a red herring, anyway, because it doesn't take into account whether your weight is due to fat, muscle or water. In a hypo it's more likely to be due to water than anything else. Hypos usually retain water.

As I said, weight can be used as a rough guide to someone after a thyroidectomy for a starter dose, but it will need constant testing and adjusting after that. Sor some people it will be to much and for others too little. Are needs are all different.

The protocol for dosing any hormone is to start low and increase slowly. For levo that means starting on 25 mcg for children and the over 60s and those with a heart condition, and increasing by a maximum of 25 mcg every 6 to 8 weeks until you feel well and the symptoms are more or less gone.

As for conversion, I cannot see for the life of me how height or weight would have any connection. Conversion is carried out by a deiodinase (protein) removing one atom of iodine. T4 has 4 atoms of iodine, so T3 will have 3, etc. Certain conditions like a fever, or taking beta blockers, etc. can have an effect on the efficiency of the deiodinase - and sometimes the cause is never determined - but highly unlikely that the BMI will have any effect. You can be a poor convertor whatever your size or shape, and vice versa.

What's more, one cannot prove a negative, so how can I tell you why something won't affect it. I can only tell you that it's not something I've never heard of and if anybody knew it did have an effect on conversion, the news would quickly spread. :)

Not what you're looking for?

You may also like...

T4 split dosing making instant difference!

Hi all, I posted on her about a week ago about trying T4 split dosing and it made an instant...
TiredMummy profile image

dosing changed

Just to let you know I have atrial fibrillation directly caused by hyperthyroid about 25 years...
Gilli54 profile image

Dosing T3Cm

Hi I just started the T3CM 6 days ago and I dose at 4.30 am. My heart rate upon waking is 78 and...
ElainedeBeaux profile image

Advice on TSH levels please

I’m a regular reader of this forum and have had some excellent advice in the past. I’m hypo after...
Dlm3557 profile image

Advice on dosing

Hi, I have decided to address my thyroid, low T3 in particular, urged by my integrative doctors....
cleo26 profile image

Moderation team

See all
Buddy195 profile image
Buddy195Administrator
RedApple profile image
RedAppleAdministrator
PurpleNails profile image
PurpleNailsAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.