Stopping B12 before blood test?

[leannemcc19]

Guys I'm ordering the B12 advanced profile and thyroid plus 11 from blue horizon and I want to know if I should stop taking my B12 supplements before I do the test? I also take a tablet with the b12 that is calcium and magnesium so do I need to stop taking these? The only other tablets I take are levothyroxine and paroxetine but I'm assuming these don't matter as long as I don't take the levo before I do the finger prick? Please correct me if I'm wrong. Thanks

[jimh111]

I know taking B12 messes up the test. I've seen a recommendation to leave two weeks after a B12 injection.

[greygoose]

Four months is the necessary time to stop B12 supplements - unless you're getting an active test.

Do you really need to take calcium? It's not a good thing to take. But, if you have to take it, at least take some vit Ks-MK7 with it.

[leannemcc19 in reply to greygoose]

It does include the active B12 so can I take it or leave it? I don't like the idea of going four months without it as I feel the lack of B12 increases my anxiety symptoms. I take the calcium because there is chromium and I read that either the calcium or magnesium helps that absorb into your body. Why should I not take it? I thought it was safe. Thanks

[greygoose in reply to leannemcc19]

Well, you know how, if you live in a chalky area, your kettle gets covered in lime scale? Well, so do your arteries, when you take those chalky calcium supplements. They are very difficult to absorb, and you risk a heart attack and kidney stones - especially if you don't need it in the first place! You should get tested for most things before taking them.

How's your vit D? ¨Probably low, this time of year. Get that tested, and supplement accordingly. The vit D3 will increase your absorption of calcium from food. So, then, you take some vit K2-MK7 to make sure that extra calcium goes into the bones and teeth, and not the soft tissues. Taking calcium supplements is like swallowing lumps of chalk, and not safe at all. Besides, it's very unlikely, in the Western world, that you are deficient in calcium. And, it's not a good idea to take anything you don't need.

Of course you wouldn't want to stop your B12 for four months, nobody would. But, if you're having the active test for B12, you don't have to, that's for the serum test. But, as you didn't specify...

[leannemcc19 in reply to greygoose]

I did actually have my calcium tested and was on the low end of normal so I didn't actually think it would be a bad thing to increase this in the short term. My vit d will be tested as part of the thyroid +11 group of tests so I won't know if that's low yet.

As for the b12 I didn't specify as this is all new to me so I'm not sure what's relevant and what's not but it's good to know I can keep taking it, i know it was also low normal by gp standards but I felt too low given I was experiencing symptoms so I'm not wanting to stop it if I don't absolutely need to. Thanks very much for your replies, very helpful 😊

[greygoose in reply to leannemcc19]

If your calcium was low normal, you should increase it by eating more calcium-rich foods, not by taking supplements. It's not so much the calcium that is bad, it's the supplements themselves.

[QUE6T-33 in reply to greygoose]

So how long should you stop taking B12 supplements before an Active B12 test, Medichecks have said 2 weeks.

[SeasideSusie Remembering in reply to QUE6T-33]

I asked Medichecks this question because when cautions about biotin were mentioned when doing blood tests they didn't mention this but they said to stop B12 which was confusing for people. So I asked them to clarify. This is their reply:

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.

Personally I don't think it even needs to be left off for one week if you want to know what the B12 supplement is achieving, taking it until the day before then testing gives a measure of what the supplement is doing and on that result you either adjust your dose or leave it as it is. If you want to know what your body holds on to then you leave the B12 supplement off for 4-5 months.

[QUE6T-33 in reply to SeasideSusie]

Really appreciate that info - thank you! I was just reading the St. Thomas’s info. Suggests stopping one month prior testing Active B12. However, I get what you say. But will one month show if your level of supplementation is ok or enough time to reflect what your body is holding on to. I’ll think on that. The Viapath test is well respected, so I guess wait a month.

[helvella Administrator in reply to SeasideSusie]

The statement from Medichecks is junk!

Surely, if you are taking a high dose biotin supplement for MS, then you need a longer washout period - not shorter!

Nonetheless, few take more than 5000 micrograms of biotin.

[SlowDragon Administrator]

If your vitamin D is low, that may account for calcium being on low side. Extremely common to be low vitamin D with Hashimoto's (high antibodies)

If/when you supplement vitamin D, calcium will rise automatically without adding extra.

The Blue Horizon plus eleven test will tell you more on vit D, folate, ferritin and B12

As you have Hashimoto's then you may find adopting 100% gluten free diet can really help reduce symptoms, and lower antibodies slowly over time too.

Selenium supplements can help improve conversion of T4 to T3 and may also lower antibodies

Links to gluten, low D and treating the root causes of Hashimoto's

hypothyroidmom.com/92-of-ha...

chriskresser.com/the-gluten...

thyroidpharmacist.com