Do we need to stop taking vitamin d before a blood test for checking vitamin d level?

[Caroline888]

Hi all,

In a week's time, I will fill two vials (hopefully!) with blood for a Medichecks Thyroid Check Ultravit. I know to stop taking biotin and iron supplements for a week before doing the test but what about vitamin d since the Ultravit does test vitamin d levels? Do I carry on taking vitamin d as usual? Obviously I will not take any supplements on the actual day of the test until after the blood draw.

Your advice would be greatly appreciated.

Best wishes

Caroline

[humanbean]

There are differences of opinion.

I always stop absolutely every pill and supplement I can for 7 days before testing unless I consider them to be essential e.g. pain relief is something I consider essential.

Other people stop different things for different lengths of time and vitamin D is one that some people take up to and including the day before the test then skip it until after the blood draw.

[humanbean]

I would say that whatever decisions you make on stopping / not stopping supplements and meds, try to stick to those same conditions from now on for every test.

[Caroline888 in reply to humanbean]

Thanks humanbean. So clearly there’s no hard and fast rule about whether or not to take vitamin d before testing.

I’ll probably take my last pill 24 hours before drawing the blood. I only take 2000 i.U. daily and my thinking is that if it were summer I could get many times that just walking to the surgery.

As you say, it is sensible to be consistent and in the past I’ve had blood taken without any warning, i.e. after taking my usual vitamin d pill. So for comparison purposes I guess I should carry on taking vitamin d until the day of the test.

Thank you for taking the trouble to reply.

Best wishes

Caroline

[Suzi_]

Is there any way to ask the dr where the blood is drawn? Stopping vit D sounds like a good option but asking the doctor would be your best bet. I am in USA and that’s what I do, it may be different in UK.

[Caroline888 in reply to Suzi_]

Hi Suzi,

Thank you so much for replying.

Actually I won't be having blood drawn at the surgery. This is a blood test kit bought from a private company that does lots of different blood tests and this particular kit involves filling two vials with blood from finger pricks😟.

However, you are quite right, I could contact the company and ask but now I've been advised that there is no specific ruling as to whether or not vitamin d should be stopped, I will probably carry on taking it until the day before. As humanbean has said, it's probably most important to be consistent, and I have had several blood tests for monitoring vitamin d over the past few years when it never even occurred to me to stop taking it. Without the advice of Thyroid UK I would not have known to stop biotin and iron supplements either! Thank goodness for this site😊.

Thanks again for taking the trouble to reply.

Best wishes

Caroline

[SeasideSusie Remembering]

Black Country Pathology (City Assays) is the NHS lab which does Vit D testing for the public.

Watch the film they have produced "Doing the test" which is near the bottom of the page in this link :

vitamindtest.org.uk/index.html

Towards the end of the film (around 2min 30secs I) it tells you there is no need to stop Vit D supplement before the test, just don't take it on the day of the test until after you've completed the test.

[Caroline888 in reply to SeasideSusie]

Thanks Susie, that's brilliant! I had the feeling I'd seen that precise advice somewhere before (probably from you) but couldn't find it on the site.

Thank you so much for sending me the link.

Best wishes

Caroline

[Fruitandnutcase]

First time I had Vit D tested using City Assays the person I spoke to to ask how long to stop for when I ordered the test said to carry on with my regular Vit D so I’ve never stopped Vit D when doing a blood test. I’ve since had other bloods done where I have been told to stop certain vitamins.

[Caroline888 in reply to Fruitandnutcase]

Thanks Fruitandnutcase. As you have confirmed, it looks as if continuing to take vitamin d right up to the day of the test and then just taking it after the blood draw seems to be the right thing to do.

Seasidesusie sent a useful link which also confirms that we don’t need to stop taking it.

Thank you so much for taking the time to reply😊.

Best wishes

Caroline