Biotin interference with Thyroid bloodwork

[Dydee]

I am due for follow up blood work and just remembered that biotin interferes with the test results. How far in advance must I quit taking my B complex which has 100% daily requirement of Biotin? My last TSH a few months ago was .03, super low for me. I usually run between 1.5 and 2. But my FT4 was 1.6 (.8 to 1.8 norm. range) and T3 was 134 (76 to 181 norm. range). I had tapered down to 2.5 mg of Prednisone for my PMR last testing. I am 81 so I'm sure things are changing because of age also and now I'm down to 2 mg of Pred.

[helvella Administrator Thyroid UK]

Dydee,

Hopefully this might help:

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.

helvella.blogspot.com/p/hel...

[Dydee in reply to helvella]

Thank you so much. It surely did help. The amount of biotin in my supplement isn't high enough to interfere with the test results. Great to know.

[Guineapiggy in reply to helvella]

Just to clarify, my daily supplements have 150 mcg biotin in them. Does this mean that I don't need to stop them before testing. I was due to test this morning, remembered I hadn't stopped the supplement for a week so didn't do the test! Wish I had seen this question earlier this morning!

[helvella Administrator Thyroid UK in reply to Guineapiggy]

At that level, I suggest a couple of days should be fine.

Your current level might make a difference to the results, but fairly minor. Trouble is, when reviewing results there will be a point at which someone's view flips from "OK" to "needs adjustment" and even a small difference could push you one way or the other. If the test is purely for your own eyes, you can simply accept that they could have been higher or lower if you had stopped the biotin - and make a note so you don't forget in future, But if for a doctor, it's as well to play safe.

[Guineapiggy in reply to helvella]

Many thanks.

[Dydee in reply to helvella]

After determining the 30mcg of Biotin I was taking wasn't a test changer, I thought I'd report back about my lab results. This was my annual physical with special attention to my Thyroid. I had the doc order a full recommended panel for my thyroid, vitamins, minerals, and full range of thyroid tests. ALL came back in the middle of the normal range. Woo Hoo!!!! As previously mentioned my TSH last year came back point zero 1, a follow up 3 months later was point zero 3. So my new test came back point zero 8, the only thing that was a bit low. All my other bloodwork for cholesterol, kidney and liver function, etc. also came back in the middle of the normal range. At nearly 82 I sure have reason to celebrate the results. So for now I guess I will be staying on 100mcg Levothyroxine, and 5mcg Liothyronine.

[Dydee]

I guess I should have included the mcg of Biotin but didn't have my glasses on when I read it and could only make out the 100% LOL Mine is only 30 mcg so shouldn't have any affect on the test.