Effect of vitamins on thyroid blood test

[carer999]

When I have my next thyroid blood test I have read that you shouldn't take biotin for 4 days before the test so I will stop the vitamin b complex. Are there are other vitamins or minerals that impact the result. Curently I take Selenium and vitamin D. Do I need to have a so many days interval between the B12 injection and the thyroid blood test. If I do, any suggestions on how long should I wait. Thanks.

[SeasideSusie Remembering]

Nothing else needs to be avoided for thyroid tests, but I would take them after the blood draw.

[carer999 in reply to SeasideSusie]

SeasideSusie apart from leaving off anything which has Biotin, does that mean I can have a B12 injection the day before?

[SeasideSusie Remembering in reply to carer999]

I can't see why not, it will raise your B12 level, I wouldn't think it would affect your thyroid hormones. Biotin is left off purely because Biotin is sometimes used in the testing procedure so the result would be skewed if biotin is supplemented.

[G2G2 in reply to SeasideSusie]

Is it any dose of biotin? B complex I take has 200 mcg of biotin. Does biotin skew the result up or down? Thanks.

[helvella Administrator Thyroid UK in reply to G2G2]

You cannot be sure what impact, if any, biotin will have on the results. Some will go up, some down, some will not be changed. Some testing relies on a process which binds biotin. Many don't.

The amount of biotin is difficult. Ordinary dietary intake is fine. The effect came to prominence due to Multiple Sclerosis patients taking very high doses but has also been shown at lower doses - quite how low, I don't know.

For lower doses, two or three days without is probably adequate.

[jgelliss in reply to helvella]

helvella speaking about vitamins do you personally supplement with "Selenium"? I find that years ago my NP gave me Selenium when I was on T-4 only I guess because I was not converting well . Now that I'm dosing with NDT + T-4 I find that I don't tolerate Selenium well . I get many symptoms sweating more skin breakouts hair loss anxiety . My daughters glucose levels went higher with Selenium . I was on 200mcg Selenium .

[helvella Administrator Thyroid UK in reply to jgelliss]

No - I don't supplement selenium.

I'd be so much happier if we could readily get a selenium test, supplement as appears needed, test again, and keep on like that.

We only need a small amount of selenium - varies a bit but usually suggested to be about 75 micrograms a day. There's bound to be some in our diet so we only need to make up the shortfall between what we already get and what we need. Of course, if very low, a short period on a higher dose might make sense. (I don't know how efficiently we absorb it, either.) It is essential for some of the thyroid-related enzymes. But too much is most definitely bad.

[jgelliss in reply to helvella]

Thank You so much for your very kind reply . I totally agree with you .If we can get it through our food why supplement unless we need more .

[G2G2 in reply to helvella]

Thanks

[SeasideSusie Remembering in reply to G2G2]

There is lots of information about biotin affecting blood results. Advice is to just avoid it for a few days before the test to be sure your results aren't affected.

google.co.uk/search?source=...

[G2G2 in reply to SeasideSusie]

Thanks!

[SlowDragon Administrator in reply to G2G2]

biotin can falsely affect test results in variety of ways

So best to stop 3-5 days before any blood tests

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

endocrinenews.endocrine.org...

[G2G2 in reply to SlowDragon]

Thanks

[vocalEK]

I have taken biotin for years in hopes of stopping the ugly, painful breakage of my nails. When 5,000 units did not help, I upped my daily dosage to 10,000. Still no improvement. Here are my test results, the latest taken after I went off all vitamins for 2 weeks before testing.

Range 10/12/2018. 3/13/2018. 10/24/2017. 10/17/2017

TSH 0.300 - 4.200 uIU/mL 0.968 0.626 0.803

FT4. 0.60 - 1.70 ng/mL 1.6 1.7 2.08

FT3. 2.57-4.43 pg/mL 2.3 2.64

[vocalEK in reply to vocalEK]

Crap. This editor did not keep my spacing. I'll try a screen shot.

Darn, I cannot get image to paste in. Is there a trick to this?

[SlowDragon Administrator in reply to vocalEK]

Suggest you put up a post of your own.

Your results suggest low FT3

You need vitamins and antibodies tested too