Blood Test - Medichecks B12

[Ste1]

Hi, advice needed please. Just about to get a Medichecks Advanced Thyroid Test done and I note that they say the following "Do not take vitamin B12 for two weeks prior to this test. If your B12 is prescribed ask your doctor whether you should stop before testing". Is this correct about needing to stop B12, I have seen previous posts referring to stopping Biotin but not B12 on its own.

Any advice appreciated.

Kind Regards

Steve

[SeasideSusie Remembering]

Ste1

I asked this question of Medichecks a while back and got this reply:

I have discussed your query with our medical director he has advised the below:

Biotin supplements.

Biotin can affect the results of any test which relies on antibodies to perform the measurement. It is wise to assume that any hormone or vitamin test will be affected, which means that the majority of our test panels can be affected by biotin supplements.

The issue with Biotin only affects people who take high dose biotin supplements. The manufacturers of the laboratory tests define this as 5000 mcg per day or more.

We are recommending people do not take high dose biotin supplements for 24 hours prior to having their blood drawn.

If they are taking high dose biotin for medical reasons (e.g. multiple sclerosis) then a shorter washout period of 8 hours can be used.

Vitamin B12 supplements.

The answer to this depends upon what they are wanting to assess.

To work out whether B12 supplements are meeting the body's requirements we recommend not taking supplements for one week prior to having their blood drawn.

If a customer wants to assess whether they have an underlying B12 deficiency then it can take months (and potentially up to two years) for levels to fall to their natural levels after stopping supplementation. In this instance we would not recommend.

So it depends what you want from the B12 test. I look at it this way:

1) If you do take a stand alone B12 supplement and want to see what B12 level it is achieving, then continue to take it and the result will show if you are taking enough or can now drop the supplement and maybe maintain the level with a B Complex. Don't take it before the blood draw on test day.

2) If you take a stand alone B12 supplement and want to know what your body is holding on to then you leave it off for 4-5 months.

If you've got the test there ready to do, test and post tomorrow. Don't do test today and post today or tomorrow unless you have a Sunday postal collection (which I don't think anyone does any more). As there are still delays with the post I'd be inclined to use Royal Mail's Special Delivery Guaranteed Next Day by 1pm (need to go to post office counter and keep the receipt with tracking number) to make sure it gets there next day.

[Ste1 in reply to SeasideSusie]

SeasideSusie,That clears it up nicely.

Many thanks for your help.

Kind Regards

Steve