Low T4

[phronsias]

Good morning

I had a blood test last week and was told yesterday my T4 was low 5 (T4 9.0 - 19.0)

She said as I am intolerate Levothyroxine ,they wanted me to try a low dose or have another blood test in 4 weeks.I said I would take a test. My T3 is also 5 (T3 2.60 - 5.70) no TSH given and I forgot to ask. I take 60mg of liothyronine 20 at 4am 20 at noon amd 20mg at 8pm.

Any idea why my T4 is low?

I havent had a blood test in 2 years.

Thanks in advance

Frank

[SlowDragon Administrator]

As you are only taking T3 (liothyronine) it’s inevitable that Ft4 is low or even zero

That’s what you would expect for someone on only T3

Is your T3 prescribed on NHS

You need to test TSH, Ft4 and Ft3 together

Book early morning test, ideally just before 9am

Day before test split T3 into 2 or 3 smaller doses spread through the day and last dose approx 8-12 hours before test

Essential to test vitamin D, folate, ferritin and B12 at least annually

Request these are included in next test

What vitamin supplements are you currently taking

[phronsias in reply to SlowDragon]

Hello

Thanks for your reply, my T3 is prescribed on NHS , the problem is I never talk to the same GP and they do not know much about hypothyroidism, I dont take any vitamin supplements .

[SlowDragon Administrator in reply to phronsias]

So you should see endocrinologist on NHS annually

explain to GP your liothyronine is prescribed on NHS. This is T3. Levothyroxine is Ft4.

As you aren’t taking Levothyroxine Ft4 will be low/zero

GP needs to write on blood test form

“Patient is taking liothyronine ONLY

Testing TSH, Ft4 and Ft3 required. Plus vitamin D, folate, ferritin and B12”

Nether levothyroxine or T3 work well if vitamin levels are not optimal

Essential to test vitamin D, folate, B12 and ferritin at least once a year

Many thyroid patients need to supplement at least Vitamin D and vitamin B complex continuously to maintain vitamins at GOOD levels

[phronsias in reply to SlowDragon]

what Vitamin D and vitamin B complex do you suggest? brand name would be helpful,TIA

[SlowDragon Administrator in reply to phronsias]

Well obviously you need to test first before considering any vitamin supplements

[phronsias in reply to SlowDragon]

Thanks

[phronsias in reply to SlowDragon]

The last time I saw my endocrinologist was 3 years ago.

[tattybogle]

Your T4 is low because you are only taking T3.

While we are taking any replacement thyroid hormone (whether T4 or T3) it turns down our own thyroid's attempts to produce T4/T3, because it lowers our TSH .

TSH is what drives the thyroid to make more T4/T3 .... The lower the TSH goes , the less the thyroid will bother to make T4 / T3.

also ....T3 also has a relatively stronger effect on lowering TSH than T4 does .

also..... for reasons no-one has totally explained/proved yet .. real life experience of peoples results when adding T3 to levo shows that for most people ,adding any T3 to levo ,lowers their T4 anyway . (even when they still take the same dose of Levo , and even in patients who don't have a thyroid of their own left to complicate matters)

Some people seem to feel perfectly well with a very low T4 when they take T3 only.. and some don't.

But IF you feel well . then there isn't any particular reason to worry about having a low fT4 .. it's main job is to be there as a store cupboard so your cells can make enough T3 from it on demand . but if you have enough T3 from a tablet and you can be sure of taking it regularly , there is not so much need for a long term T4 'store'

However , some cells in the body ( brain, i think ., but forgotten to be honest ) do 'prefer' to make their own T3 from T4 , rather than take ready made T3 from the bloodstream .. and so there may be some reasons to be concerned about low T4 if you don't seem to be functioning ok.

[phronsias in reply to tattybogle]

Thanks, I sometime get headaches and pain in my eyes

[SlowDragon Administrator]

What’s the cause of your hypothyroidism

There’s nothing on your profile

For full Thyroid evaluation you need TSH, FT4 and FT3

plus both TPO and TG thyroid antibodies tested at least once

About 90% of primary hypothyroidism is autoimmune thyroid disease, usually diagnosed by high thyroid antibodies 

Autoimmune thyroid disease with goitre is Hashimoto’s

Autoimmune thyroid disease without goitre is Ord’s thyroiditis. 

Both are autoimmune and generally called Hashimoto’s.

Low vitamin levels are extremely common when hypothyroid, especially with autoimmune thyroid disease (Hashimoto’s or Ord’s thyroiditis)

20% of autoimmune thyroid patients never have high thyroid antibodies and ultrasound scan of thyroid can get diagnosis 

In U.K. medics hardly ever refer to autoimmune thyroid disease as Hashimoto’s (or Ord’s thyroiditis)

Private tests are available as NHS currently rarely tests Ft3 or all relevant vitamins

List of private testing options and money off codes

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins

bluehorizonbloodtests.co.uk...

If you can get GP to test vitamins and thyroid antibodies then cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code

thyroiduk.org/getting-a-dia...

monitormyhealth.org.uk/

Monitor My Health also now offer thyroid and vitamin testing, plus cholesterol and HBA1C for £65 

(but no thyroid antibodies)

monitormyhealth.org.uk/full...

Only do private testing early Monday or Tuesday morning. 

Watch out for postal strikes, probably want to pay for guaranteed 24 hours delivery 

[phronsias in reply to SlowDragon]

I have a goitre

[SlowDragon Administrator in reply to phronsias]

So did you have thyroidectomy?

[phronsias in reply to SlowDragon]

No

[SlowDragon Administrator in reply to phronsias]

So quite likely your hypothyroidism is autoimmune thyroid disease also called Hashimoto’s

Look at all your historic test results

You should have had Thyroid Peroxidase antibodies (TPO) tested at diagnosis

Ideally you need BOTH TPO and Thyroglobulin (TG) antibodies tested

But NHS only tests TG antibodies if TPO are high/abnormal

Significant minority of Hashimoto’s patients only have high TG antibodies

If cause of your hypothyroidism is autoimmune then you need coeliac blood test before trialing strictly gluten free diet

High percentage of autoimmune thyroid patients find strictly gluten free diet and/or dairy free diet helps ot is essential

[phronsias in reply to SlowDragon]

Thanks for your help! ts a lot to think about.