Preparing for antibodies test

[SleepingDisco]

Good morning, my GP has approved an antibodies test and a full blood count (the only 2 things that were missing from my last test on 3rd October).

I’ve never had an antibody test before

Am I okay taking b12 & b complex prior to both these tests or should I refrain until after?

And should I take my Levo dose on the morning of the blood test too?

Many thanks for helping x

[SeasideSusie Remembering]

SleepingDisco

Am I okay taking b12 & b complex prior to both these tests or should I refrain until after?

As previously advised here:

healthunlocked.com/thyroidu...

you must stop any supplements that contain biotin 5-7 days before blood test because biotin can falsely affect test results (it’s used in equipment in many labs)

B Complex contains biotin so you need to stop your B Complex for a few days before any blood test, notjust thyroid but any blood test. The length of time depends on the dose of biotin. Most B Complex supplements contain around 400-500mcg which is a low dose so leaving off for 3-4 days should be enough. Stand alone biotin or hair/nail supplements which contain high amounts such as 5-10mg should be left off for 7 days.

And should I take my Levo dose on the morning of the blood test too?

No. Last dose of Levo should be 24 hours before the test, adjusting time the day before if necessary. Even though you haven't been told that there will be a thyroid panel (TSH, FT4/FT3), it's possible it may be done so rather than risk false results it's best to take your Levo after the test.

I would also do this as a fasting test in case there's anything in the FBC that requires fasting, they don't always tell you. Hopefully you've got an early appointment so just have water before you go and then breakfast/tea/coffee, etc when you return.

[SleepingDisco in reply to SeasideSusie]

Thanks SeasideSusie, brilliant advice as always. I didn't realise B-Complex contain biotin, as I've not worked out which brand to take yet. But great to know and will do all the above for the test.