I’ve just had a recent blood test and surprisingly my TSH has fallen. I’m on 75 of levo. Not having any symptoms of over active thyroid. I checked my multi vitamin and it has Biotin in it? Would this make a big difference- should I ask for re-test?
Your Serum TSH level history
The table below shows your Serum TSH level from 3 August 2023 to 20 February 2024
Date Result
20 February 2024 0.17 mIU/L
27 November 2023 5.67 mIU/L
22 September 2023 4.12 mIU/L
3 August 2023 5.32 mIU/L
just testing TSH when on replacement thyroid hormones is completely inadequate
Multivitamins never recommended on here
Most contain iodine which can cause issues
Never supplement iron unless tested and deficient
ALWAYS test thyroid early morning, ideally before 9am, only drinking water between waking and test ….last dose Levothyroxine 24 hours before test
You need TSH, Ft4 and FT3 tested together
Plus vitamin D, folate, B12 and ferritin at least annually
My vitamins were done when I was diagnosed. All okay apart from zinc which I take a supplement for. Also take vit D and A and then a multivitamin. Will stop the multivit and ask for a re-test.
Retest vitamin D twice year and folate, B12 and ferritin at least annually
Unless you have Hashi's, yes, it does look like it's made a difference.
I do have Hasis (the high anti bodies)
OK, so you could be having a Hashi's 'hyper' swing, and that's what's causing the low TSH.
Would it be usual for the tsh to drop so dramatically with only at 25g increase in levo? How long should I leave the re-test since stopping multi vit?
Who can tell. The TSH is entirely unpredictable. But probably, yes.
Wait at least a week before retesting. And, if I were you, I'd put that multi-vit in the dustbin, where it belongs. We do not recommend muli-vits for many reasons. Basically, they're just a huge waste of money. Supplements should only be taken if you need them, and to know if you need them, you need the nutrients tested. More is never better and could be dangerous.
helvella - Biotin supplementation and testing
A short article about how and why biotin can affect blood tests. Includes information about how to avoid any problems.
How much will timing and biotin affect results?
Biotin & thyroid tests
Tests after Biotin stopped
TSH higher after stopping Biotin
