New blood results

[nat10]

Having a phone call tomorrow to review medication, so please can I ask what anybody thinks I should ask, still having days where I am tired and needing an afternoon snooze.

Bloods march 2021

TSH. 0.39 (0.27-4.2)

FT4. 16. (12.0-22.0)

FT3. 4.5. (3.1-6.8)

Bloods June 2020

TSH. 0.05

FT4. 16.7

FT3 4.5. Same ranges

I have been on 75 Levothyroxine since Jan 2020, diagnosed November2019

Thank you for any advice.

[SlowDragon Administrator]

Was this test done as early as possible in morning before eating or drinking anything other than water and last dose levothyroxine 24 hours before test

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

When were these last tested

What vitamin supplements are you currently taking

Is cause of your hypothyroidism autoimmune thyroid disease also called Hashimoto’s diagnosed by high thyroid antibodies

How much do you weigh in kilo

Results suggest you are under medicated

Ft4 is only 40% through range

Ft3 slightly less at 38% through range

So good conversion but in need of dose increase

Most people fell better when Ft4 and Ft3 are at least 60% through range

guidelines on dose levothyroxine by weight

Even if we frequently don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until eventually on, or near full replacement dose

NICE guidelines on full replacement dose

nice.org.uk/guidance/ng145/...

1.3.6

Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Also here

cks.nice.org.uk/topics/hypo...

gp-update.co.uk/Latest-Upda...

Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months. RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

BMJ also clear on dose required

bmj.com/content/368/bmj.m41

bestpractice.bmj.com/topics...

[nat10 in reply to SlowDragon]

Thanks for the reply

Last ferritin tested oct2020 58.64 (15-150) was 14.05 in jan20.

Vit d 175 (50) June 20

Serum B12 664 (197-771) jan 20

Serum folate 10.4 (3.3-19.3) jan 20

Yes to Hashimotos, weight around 68kg

Supplement with zinc 15mg,

selenium 200mcg

Spatone 5mg iron

B12 10mg

Vit c. 500mg

Magnesium 375mg

Vit k (mk 7) 100mcg

Vit d 25 during winter 10 during summer

Friendly bacteria

Bilberry,lutein and zeaxanthin

[SlowDragon Administrator in reply to nat10]

So guidelines of 1.6mcg per kilo of your weight

Weight 68kilo x 1.6mcg = 108.8mcg as the likely daily dose levothyroxine required

760mcg in total, per week - so you might require an extra 50mcg levothyroxine per week

As GP to follow guidelines and increase dose to 100mcg everyday and retest 6-8 weeks after each dose of levothyroxine

[nat10 in reply to SlowDragon]

Forgot to say, Blood test was done before food and drink and 24hrs from last dose.

[pennyannie]

Hello Nat ;

I see from your profile we are diagnosed with Hashimoto's AI thyroid Disease.

Looking at the above your results haven't really changed much and since you still have some symptoms of hypothyroidism maybe a 25mcg increment in T4 will help you .

Your T4 is coming in at just around 40% through the range and your T3 is well balanced and coming in at around 38% : and generally we feel better when both T3 and T4 are in the top quadrant of their ranges so I think I would be asking for a dose increase in your T4 thyroid hormone replacement.

The accepted conversion ratio when on T4 Levothyroxine only is 1 / 3.50 - 4.50 - T3 / T4 : with most people preferring to come in at around 4 or under :

So to find your conversion ratio when on T4 only you simply divide your T3 into your T4 and we get 3,50 showing excellent conversion of the T4 into T3.

Sadly if your doctor only looks at the TSH there maybe a conversation about your TSH being too low and an increase in T4 not advised.

Too low a level of T3 and you have symptoms of hypothyroidism whilst too high a level of T3 and you my well have symptoms of hyperthyroid.

Quite where your level of T3 needs to be for you to be symptom free is not known, so as you still have tiredness and that pm slump it sounds like you need a bit more thyroid hormone replacement to get you through the rest of the day.

Optimal conversion of T4 into T3 can be compromised by lowish levels of ferritin, folate, B12 and vitamin D - and whilst your conversion doesn't currently look to be a problem, since you have an autoimmune thyroid disease, it's worth keeping an eye on your core strength vitamins and minerals.

[nat10 in reply to pennyannie]

Thanks for the reply, I am hoping to get an increase as lower ft4 on 75 Levothyroxine than when I was on 50 Levothyroxine.

[pennyannie in reply to nat10]

Yes, ok then - it's the first necessary step.

You may also feel less tired when your ferritin reaches higher in the range :

I've found I feel at my best with a ferritin of around 100 ;