Me again regarding those high T3 results. So after posting last time I realised that one of my postpartum supplements has biotin in it- I’m wondering how certain can I be that biotin is behind my crazy results - does it always interfere? Also any advice on how long do I need to wait to retest after stopping the supplement?
I also just wanted to ask about testing on NDT - I read on one of the posts to split the dose in 3 and take every 8h. Is this new? I’ve always took full dose and waited 10h before testing. Been feeling very well on the dose the results suggest for years. I’m curious whether I should change to this new technique? Or is my old technique also acceptable?
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AnnaSo
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So after posting last time I realised that one of my postpartum supplements has biotin in it- I’m wondering how certain can I be that biotin is behind my crazy results - does it always interfere? Also any advice on how long do I need to wait to retest after stopping the supplement?
According to the different labs (NHS and private) yes, biotin does give false results. However, it's the amount of biotin that you need to be careful of.
High dose biotin, such as the amount in a stand alone biotin supplement or hair/nail supplement - typically 5mg or 10mg needs to be left off for 7 days before testing. The amount in a B Complex - typically around 400mcg - should be OK to leave off for 3 days.
I also just wanted to ask about testing on NDT - I read on one of the posts to split the dose in 3 and take every 8h. Is this new?
It's what's generally suggested here.
I’ve always took full dose and waited 10h before testing. Been feeling very well on the dose the results suggest for years. I’m curious whether I should change to this new technique? Or is my old technique also acceptable?
If you are well on your dose and this works for you then you might want to continue doing it this way. It's down to what suits the person at the end of the day.
This is very interesting Anna, I was recommended biotin for hair and nails. I haven't so far taken it but had no idea that it could interfere with T3 uptake. I really hope this is the answer for you!
I don't think you need to worry too much about splitting your dose of NDT if you haven't previously done so. I've only ever taken it as one dose a day first thing in the morning, because that's what Dr Skinner, the doctor who first diagnosed and treated me, told me to do. I then wait a day before having tests done. My current endocrinologist mentioned splitting it into three doses a day, but when I told him I'd always taken one dose, he said that was fine as it was working well for me.
Apologies. If it interferes with test results but not uptake etc., then it does not affect how the person feels? And if one were to ignore test results, or not have any done while taking biotin, then it's fine to take it?
If you need your supplement that contains Biotin there is no problem with it. All you need to do is leave it off for 3-7 days before any blood test, 3 days for a small dose of biotin such as 400mcg, 7 days for a large dose such as 5mg or more. This is because most labs use biotin in the testing procedure and if we also take Biotin then this gives false results.
Is panthenol related in any way to biotin?. This post made me check the stuff I use for my nails and I know panthenol is a B vitamin. I ask because just had my thyroid panel done (awaiting results).
Thank you, that’s also what I always been doing and seemed to have worked well for me. Also how wonderful you got to be looked after by dr Skinner! Very lucky
Yes it’s only the blood test that the biotin effects so something to be mindful of if you take that hair and skin supplement
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