Vitamins & supps prior to blood test

[Anniewoz1]

Hi everyone

I’ve a medicheck ultra vit test to do next week.

It states to leave off b12 for a week prior to blood draw.

Does this also apply to biotin and boron ?

Many thanks

[SeasideSusie Remembering]

I really don't understand why they are saying this. They have confirmed to another member that it's biotin that should be left off for 7 days prior to doing a test with them. Their email reply is in the first post in this thread:

healthunlocked.com/thyroidu....

There is no mention of leaving off B12. To get a baseline of your B12 level you would need to be off B12 supplements for 4-5 months.

So leave off biotin or a B Complex containing Biotin (B7) for 7 days. If taking iron tablets leave those off for 7 days also, and don't eat liver, etc, in the week before the test as Ferritin is being tested. Everything else, just take after the blood draw on the day.

[Anniewoz1 in reply to SeasideSusie]

Thanks SeasideSusie

[SeasideSusie Remembering]

I think you left out an important piece of information in your question above, as I see that you have asked this elsewhere and said that Medichecks instructions say:

"Active B12 levels can be affected by use of vitamin B12 supplements."

My answer to you here was based on the fact that you asked about the Ultravit test and I said that Medichecks state that biotin can affect levels of thyroid hormones as confirmed in the email to the other member.

If Medichecks say that taking B12 supplements can affect Active B12 levels then I'm sure they are right. I'm surprised you didn't mention that it was Active B12 that you were talking about where B12 supplements were concerned when I said I didn't understand why they were saying to leave them off.

[Anniewoz1 in reply to SeasideSusie]

I am so sorry for any confusion, there was none intended.

On the other post you mention I was able to “copy and paste” straight from the email from medicheck.

Please accept my apology SeasideSusie,

[Gambit62 in reply to SeasideSusie]

just to clarify - biotin doesn't affect thyroid levels but it does affect the 'accuracy' of the test - the tests use a method called mass spectrometry which means that sometimes it can be difficult to distinguish one chemical from another that has a similar mass/charge ratio. So, it's difficult/impossible to distinguish biotin from thyroid hormones with the result that taking biotin too close to the thyroid test you can get an artificially high reading.

[SeasideSusie Remembering in reply to Gambit62]

Yes, I knew that biotin can give false results, I was trying, unsuccessfully, to condense what Medichecks said, I should have used the word results rather than levels

The medical team have also added that because biotin is an ingredient used in many lab hormone test kits this can interfere with the measurement of thyroid hormones

It does this in an inconsistent way, causing falsely elevated results from some labs, and falsely low results from others.

[Hidden in reply to SeasideSusie]

Does that include TSH? If it would always cause falsely high results I would be very strongly tempted to continue taking it to try and convince them I need an increase not a decrease of Levo which is being threatened if it is still below range next time!

One can dream...

[SeasideSusie Remembering in reply to Hidden]

Sorry Jnetti, it's all a bit vague and some articles say it's high dose biotin that causes problems but Medichecks just says to stop taking any biotin for 7 days before testing.

This is from Labtestsonline labtestsonline.org/news/fda...

Most of the published research on biotin interference covers hormone tests, such as parathyroid hormone (PTH), thyroid stimulating hormone (TSH), T4 and T3 tests, as well as tests for troponin. However, because biotin is used in so many immunoassays, scientists say it could interfere with many others.

[Hidden in reply to SeasideSusie]

As said, one can dream