b12 taken before a blood test for b12 ? - Pernicious Anaemi...

Pernicious Anaemia Society

32,672 members24,065 posts

b12 taken before a blood test for b12 ?

lcunliffegizmo123 profile image

how long do I need to be free of any b12 sublinguals before a correct diagnosis of PA ?

Written by
lcunliffegizmo123 profile image
lcunliffegizmo123
To view profiles and participate in discussions please or .
Read more about...
14 Replies
wedgewood profile image
wedgewood

My blood serum levels were astronomical when I was tested I was covered in B12 patches , and had been taking sub - lingual lozenges several times a day as I felt so desperately unwell dizzy , confused had brain fog , breathless and had numb feet . My GP didn't think my B12 was low at 150 , so I went to a private doctor who tested for the anti bodies to the Intrinsic Factor . I was lucky and showed up positive . I say lucky because you can show up negative and still have PA ( about 50 % ) apparently there are different tests for PA . Some will work even if you have supplemented like I did beforehand , some not . I don't know which one I had . I would explain the situation . Best wishes to you

PAS-admin profile image
PAS-adminPartner

Depends on how long you were taking them, how high the dosage and on your personal absorption level. But in general you can say months, at least 3, but likely even more.

That is, if you mean to test B12 (or active B12/MMA/hcty).

PA however can be tested now (or after a week) Testing for antibodies IF/PC/gastrine can be done while on treatment/supps.

(see also Pinned Posts on the homepage of the forum)

lcunliffegizmo123 profile image
lcunliffegizmo123 in reply toPAS-admin

How about 1x1mg hydroxocabalamin intra muscular ,1 last week and one the week before and test dew on the 9 th next month, also would it affect folate levels too ,and thankyou for your reply , I think I messed things up .

PAS-admin profile image
PAS-adminPartner in reply tolcunliffegizmo123

So you had two injections but not sublinguals?

lcunliffegizmo123 profile image
lcunliffegizmo123 in reply toPAS-admin

Sorry yes he did ! xx

PAS-admin profile image
PAS-adminPartner in reply tolcunliffegizmo123

I just saw your other post, you've been injecting every other day for 8 months and daily sublinguals?

Then I don't really understand your initial question?

lcunliffegizmo123 profile image
lcunliffegizmo123 in reply toPAS-admin

So sorry I was actually referring to my partner really on the other post who has been on statins for years and now is feeling breathless for the last few weeks and doc not taking him seriously ,tiredness aches and pains etc very pale so he asked me to inject him under supervision of a member of family RGN , now the gp wants to test him for B12, folate and thyroid function ! sorry didn't really want to post as him !! xx

PAS-admin profile image
PAS-adminPartner in reply tolcunliffegizmo123

ak, ok, get it now. But he hasn't been tested before? Shame..

After injections it will take some months. But he was also taking sublinguals before or not? Cause then it will be even longer.

Did he get his blood results and check everything himself? (or you?) Like Hb, iron etc?

lcunliffegizmo123 profile image
lcunliffegizmo123 in reply toPAS-admin

No he had not ever taken sublinguals only if you can call a daily multi vitamin for the last 30 yrs religiously , its really messed up now I know ,I didn't think he would ever test him as he has asked many times if his b12 could be low as he had some symptoms I had before I was diagnosed 18 mnths ago , his doc is wanting him to have the bloods early next month, I have now left a message for the gp explaining he has had 2 injections ,don't know how that will work out now xx if it will affect folate thyroid etc xx

PAS-admin profile image
PAS-adminPartner in reply tolcunliffegizmo123

no, doesn't effect the rest, but the B12 is kinda worthless..shame.

lcunliffegizmo123 profile image
lcunliffegizmo123 in reply toPAS-admin

Thankyou for the response , with my fight for a diagnosis I thought he would never get a result for blood test ,and then a fight for b12, I thought I was helping ,! just a little too late , but thankyou xx :(

lcunliffegizmo123 profile image
lcunliffegizmo123 in reply toPAS-admin

No , never been tested before xx

cgregg718 profile image
cgregg718

When I took my test, and it was on the very, very low end, and I was taking supplements. I wasn't taking very high doses, just one b12 a day, orally.

expatkerry profile image
expatkerry in reply tocgregg718

hello cgregg718, were you taking a sublingual b12 1000mcg by any chance? This question interests me too as I've been taking this dosage daily fir weeks now and my as well as my medically supervised injection every fortnight. I'm afaid the test I had today will show sky high levels that I'll have to justify.

Not what you're looking for?

You may also like...

B12 Blood test taken without warning

Hello All, I received a text from my GP surgery asking me to attend an NHS healthcheck. I called...
HKAnne profile image

Stopping B12 before blood test?

S’mae pawb, happy September🫶🏻 Here’s one for you. Some say it takes weeks or months for B12...

Blood Test for B12

Hi, I recently had a blood test fir my B12 and folat which both came back as normal (419 and 5.2)....

Blood test for B12

I have been having B12 for 4years every 12wks.All of a sudden they have asked me to go for a blood...
Chocolate41 profile image

B12 blood test

My recent results are as follows B12 219 Range 280/640 I am told this is in range and to take a...
Sewingbee24 profile image

Moderation team

See all
Gambit62 profile image
Gambit62Administrator
Foggyme profile image
FoggymeAdministrator
taka profile image
takaAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.