I have just ordered a test from Medichecks and looking at the instrctions, this one seems new:
Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed. Do not take vitamin B12 for two weeks prior to this test. If your B12 is prescribed ask your doctor whether to stop.
Is it really necessary to stop B12 for two weeks?
Following as I wondered this too. I don’t want my B12 levels to drop if I don’t need to considering how long these things take to build up.
Nor am I sure 2 weeks takes you back to baseline levels anyway, so what would be the point?
To get to baseline for B12 would take 3 months so their suggestion of 2 weeks is nonsense.
If you are just looking to find out if a B12 supplement is working well and what its achieving then you can take it right up until the day before the test.
A biotin containing supplement is different again, think most B complex's. 2 days would likely be enough for most but I allow 4 days myself to be on the safe side.
Thank you!
Regarding biotin, the problem with it is described in these threads :
healthunlocked.com/thyroidu......
healthunlocked.com/thyroidu...
healthunlocked.com/thyroidu...
medscape.com/viewarticle/97...
Biotin itself is not dangerous to humans. It is dangerous only to testing machines which use biotin as part of their testing protocol, and they can get confused and produce results that are far too high or far too low if the blood sample they are testing contains biotin.
Anyone who takes biotin should stop taking it before doing any testing. The higher the dose the longer it should be left off.
Medichecks suggests leaving off any supplements containing biotin for two days before testing. But if someone is taking lots and lots of biotin they might need to stop taking it for up to a week.
As soon as the blood samples have been taken and tested and the results have come back without obvious errors then the supplements containing biotin can be taken again.
As for B12 - I'm not sure why it is suggested that B12 should be stopped for two weeks. It takes substantially longer than that (several months) for anyone to get a baseline for their B12.
Personally, I stop taking all my supplements (including B12) for a week before doing any testing except the ones I need for my quality of life e.g. my OTC anti-depressant. But it is my choice to do that, and others may make different choices.
I have B12 injections every 12 weeks as I cannot obtain it from food or a supplement-I don't have 'intrinsic factor'. My last shot was 6th Nov. I have a thyroid test kit to do now, should I wait to use it or advise Medichecks when my last shot was?
If your test kit does not include B12 (i.e. it's only for thyroid), then your B12 injections will be irrelevant. So just go ahead and do the thyroid test.
To add to RedApple - there is lots of discussion about testing B12 blood levels after injections - saying it is poor practice, provides nothing useful, and could be misleading.
Have a look here:
Pernicious Anaemia Society forum:
AND
Vitamin B12
Bruce HR Wolffenbuttel, 1 P Julian Owen, 2 Mary Ward, 3 Ralph Green
I take granular liver capsules which have a natural source of Vitamin B12 in them. I am testing in 8 days with Medichecks but haven't stopped them as I feel so good on them.
You might want to ask the company that you are testing with that question. I would hope that if it is relevant they would say so on their instructions though.
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