What might cause a spike in FT3?

[Rollercoaster44]

I'm back again with a query. I trust the advice on this forum far more than I do my GP!!! - a huge thank you to all who provide support and such helpful advice.

Following on from my posts of several months ago my GP (or should I say GPs) continue to keep changing the dose of my levothyroxine despite resistance from me. Am getting increasingly frustrated with my local surgery as they just don't seem to want to listen to the patient, they keep doing bloods but look at them individually rather than the whole picture - have now spoken to 4 different doctors (not out of choice) and all of them have different opinions and I don't manage to speak to the same doctor more than once. Driving me nuts but know I'm not alone! Anyway my most recent NHS blood test results have me a little confused (all tests done between 9 - 9.30am, fasting with no Levo for 24hrs (any supplements stopped for 7-10 days prior to tests). What would cause the little spike in FT3 with my most recent results please - any suggestions welcome?:

29 March 2023 (on 137.5mcg Levothyroxine)

TSH 0.18 mIU/L (.38 - 5.33) -4.0%

Free T4 (fT4) 14 pmol/L (7.9 - 20) 50.4%

Free T3 (fT3) 6.8 pmol/L (4 - 6.6) 107.7%

9 Jan 2023 (on 150mcg Levothyroxine)

TSH 0.18 mIU/L (.38 - 5.33) -4.0%

Free T4 (fT4) 14 pmol/L (7.9 - 20) 50.4%

Free T3 (fT3) 5.5 pmol/L (4 - 6.6) 57.7%

10 Oct 2022 (on 125 mcg Levothyroxine)

TSH 1.25 mIU/L (.38 - 5.33) 17.6%

Free T4 (fT4) 10.3 pmol/L (7.9 - 20) 19.8%

Free T3 (fT3) 4.9 pmol/L (4 - 6.6) 34.6%

[SlowDragon Administrator]

Helpful profile

Hashimoto’s

only got one adrenal gland

Previous post shows low vitamin levels

healthunlocked.com/thyroidu...

Presumably you have working on improving these since

So you need to get vitamin D, folate, ferritin and B12 retested at least annually…..but when have been low …..every 6 months

Have you reconsidered trying strictly gluten free diet and/or dairy free diet

With Hashimoto’s levels can hop up and down

[Rollercoaster44 in reply to SlowDragon]

Hi - yes been working on vitamins. Ferritin is bit of a dilemma as its not increasing much - - have had to stop iron tablets as red blood cell count over range and one liver test abnormal, haemoglobin estimation also at top of range with haematocrit very near the top too.

Last NHS ferritin test - 29 March (2 weeks after stopping 4 months of 322mg Ferrous fumarate) 34 ug/L (11 - 307) 7.8%

Vitamin D (early March ) - 85 nmol/l (done by MMH)

B12 - Last NHS test was early Jan 2023 - 341 ng/l (145 -914)

Active B12 - MMH in March 2023 - 132 pmol/l (approx 40-210)

Folate - Last NHS test was early Jan 2023 - 15.3 ug/l (no range given)

Folate -MMH in March 2023 - 8.8 ug/l (approx 3 - 25)

[SlowDragon Administrator in reply to Rollercoaster44]

What B12 and what vitamin B complex are you taking?

very effective B12 drops 

natureprovides.com/products...

Or

B12 sublingual lozenges 

uk.iherb.com/pr/jarrow-form...

cytoplan.co.uk/shop-by-prod...

B vitamins best taken after breakfast

Thorne Basic B recommended vitamin B complex that contains folate, but they are large capsules. (You can tip powder out if can’t swallow capsule) 

Thorne currently difficult to find at reasonable price, should be around £20-£25. iherb.com often have in stock. Or try ebay 

Other options 

healthunlocked.com/thyroidu....

IMPORTANT......If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before ALL BLOOD TESTS , as biotin can falsely affect test results

endo.confex.com/endo/2016en...

endocrinenews.endocrine.org...

In week before blood test, when you stop vitamin B complex, you might want to consider taking a separate methyl folate supplement and continue separate B12

How much vitamin D and are you also taking magnesium afternoon or evening (at least 4 hours away from levothyroxine)

[Rollercoaster44 in reply to SlowDragon]

taking natures best b50 complex / multigard without iodine or iron on alternatate days plus Better You B12 spray (2 squirts daily was 4) . Vitamin D alternate 12.5/25ug…taken lunchtime. Then 150mg mag citrate after evening meal.

[SlowDragon Administrator in reply to Rollercoaster44]

so perhaps increase vitamin D and B12 a bit higher

[SlowDragon Administrator in reply to Rollercoaster44]

Iron and ferritin are difficult

Suggest reading many posts and replies by humanbean on iron and ferritin

Also I think it was Regenallotment posted recently about how tea and coffee can affect iron absorption

Post discussing just how long it can take to raise low ferritin 

healthunlocked.com/thyroidu...

Iron and thyroid link

healthunlocked.com/thyroidu...

Excellent article on iron and thyroid 

cambridge.org/core/journals...

Posts discussing why important to do full iron panel test

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

Chicken livers if iron is good, but ferritin low

healthunlocked.com/thyroidu...

Shellfish and Mussels are excellent source of iron 

healthline.com/nutrition/he...

Heme iron v non heme

hsph.harvard.edu/nutritions...

Ferritin over 100 to alleviate symptoms 

healthunlocked.com/thyroidu...

Great research article discussing similar…..ferritin over 100 often necessary 

ncbi.nlm.nih.gov/pmc/articl...

Low Iron implicated in hypothyroidism 

healthunlocked.com/thyroidu...

[jimh111]

With autoimmune hypothyroidism the thyroid can release spurts of T3 as it comes under attack.

[arTistapple in reply to jimh111]

As a matter of interest over how long a period can this go on, perhaps even before diagnosis? Do you know/educated guess? Just wondering as my symptoms of my short acquaintance with T3 were remarkably similar to my symptoms of unknown source which I suffered for many years.

[Buddy195 Administrator]

As jimh111 has said, this can happen with Hashimotos. It’s happened to me a couple of times & after the ‘FT3 spike’ settled, I actually required a slight dose increase. I only adjust Levo by 12.5mcg at a time, as I’m very sensitive to change.

[Gustie88]

occasionally low cortisol can drive up t3 in the serum.

[radd in reply to Gustie88]

Can it? Interesting. Can you provide more details or links please.

[Gustie88 in reply to radd]

Hi Radd- sorry I just replied by mistake to Rollercoaster 44. Take a peek and see what you think. Cheers.

[radd in reply to Gustie88]

Gustie88,

I had a look and could only get the abstract. I would say it’s the equivalent to the T3 raises seen in people as of yet undiagnosed. The body goes into a survival mode and will encourage higher FT3 levels to retain well-being, even at the expense of FT4. 

[Gustie88]

Increase in T3levels during hypocorticism in patients with chronic secondary adrenocortical insufficiencyin European Journal of Endocrinology.

Sorry RC44, having trouble copying links on my phone. Looks like low cortisol can cause and increase in peripheral conversion of T4 to T3 driving up T3. Could also be a reduced clearance of T3 from the body due to low cortisol. I’ve had low cortisol and have seen a concurrent rise in T3 at times. Wishing you well.

[Ajva]

can be a number of things. You may convert well so a small increase can push t3 up, reverse t3 may have increase which is where the t3 can pool in blood causing higher t3.

My t3 is always around the 6/7 mark. If you read the optimal blood test results they are always around that sort of mark. So I wouldn’t be concerned about your t3 being high if it is conversion is good.

[TaraJR]

Had anything else happened recently before the test? Eg anything stressful, a virus, any medication, any injection/vaccination?

[Rollercoaster44 in reply to TaraJR]

nope just another usual day.

[Star13]

Funny, same thing happened to me at my last test and my result looks similar to yours. I could not swear I had not inadvertently not taken my T3 that morning by mistake so waiting a bit longer for Vits to improve to retest.

[Poniesrfun]

I recently completed a CME on Low Ferritin/Low TSAT without anemia. It was focused on heart failure but applicable to other situations. This is some of the take away and points out the importance of having a complete iron panel, not jus relying on ferritin and CBC results -

Epocrates CME (probably have to have the Epocrates app) cme.epocrates.com/wf/wf.do

Mayo Clinic: mayoclinic.org/medical-prof...

[TSAT - transferrin saturation (percent of transferrin  binding capacity)]

Low Ferritin and Low TSAT “absolute” for iron deficiency ncbi.nlm.nih.gov/pmc/articl...

Iron Deficiency (ID) without Anemia: Ferritin <100 or Ferritin 100 - 300 and TSAT <20%

Iron deficiency without anemia occurs when a person's iron stores are low, but their hemoglobin levels (an indicator of the amount of iron in the blood) are still within a normal range. Symptoms of iron deficiency without anemia may include fatigue, weakness, and difficulty maintaining body temperature. This condition can progress to iron deficiency anemia if left untreated, as the body's iron stores become increasingly depleted. Iron deficiency without anemia can be caused by a variety of factors, including poor dietary intake of iron, blood loss, and certain medical conditions that impair the body's ability to absorb or utilize iron. Treatment typically involves increasing iron intake through diet or supplements, and addressing any underlying causes.

Patti in AZ

[michu1]

Hello, I have the same problem - hashimoto and strong conversion ft4 to ft3. Now I have tsh 0.25 ft4 57% and ft3 81%. When I lower my dose of levothyroxine the problem is even worse. When I take too much levothyroxine my rbc is above the norm. When I take too much vitamin d I have the same situation. Before I started taking hormone I felt similar. Hot flashes, redness, sweating, water retention and I had tsh 1.9, ft4 30% and ft3 60%. I feel hypo and hyper at the same time. I have very fast metabolism but I hold a lot of water. I have problem with breathing and I am hot. I am tired. I have low tpo antibody but tg antibody above a normal range. No doctor has helped me to this day.