Pernicious Anaemia Society

Start b12 and folic acid now or wait for PA test?

Hi, I've been to see my new gp today and taken my latest blue horizon results with me:

TSH: 4.77 (0.27-4.2)


T4 Total: 77.2 (64.5-142)

FT4 12.57 (12-22)

FT3 4.96 (3.1-6.8)

Anti-thyroidperoxidase abs 80.6 (<34)


Anti-thyroglobulin Abs 565.1 (<115) H

Vit D (25 OH) 20 (Deficient <25) L

Vit B12 238 (Deficient <140) (insufficient 140-250)


Serum Folate 8.31 (8.83-60.8) L

Ferritin 188.9 (20-150)


CRP 11.30 (<5) H

She's started me on the following supplements:

Hux D3 20000 twice/week for 7 weeks

Hydroxocobalamin 1mg/ml 6 injections over 2 weeks then on repeat prescription 1 injection every 3 months

Folic Acid 5mg 1 daily on repeat prescription for 3 months

I'll then have the tests repeated and she said we can test for PA too. I've just been getting some advice from the thyroid UK forum and they suggested asking here if I should hold off starting the injections and folic acid until having the PA test. I can't really hold the b12 injections off as I have the 6 injection appointments booked with the nurse but I could possibly push for the PA test earlier. I've only just registered with her and she's the first gp to actually listen to me so I don't want to push my luck. Is there any benefits to testing first, would it be managed or treated any differently to have a diagnosis?

Thank you x

6 Replies

if you look through the pinned posts it gives you the time scales to avoid supplementation for various tests involving B12 - IFA needs about a week since supplementation so I wouldn't delay starting the B12 injections. Ideally you should have the first injection before you start supplementing folate - ie start the folate the day after your first loading shot.

With B12 it is symptoms rather than test results that count. If you have neurological symptoms then the recommended treatment is loading shots 3xweekly until symptoms stop improving (review at 3 weeks) and then maintenance every 2 weeks.

Make a list of your symptoms and monitor how they change.


Good that your GP recognised the need to supplement B12 rather than just going on the test scores - definitely a keeper :)

1 like

Sorry I didn't see them :) I'll have a look now.

Is IFA the blood test I need to diagnose? And it's done a week after starting supplementation? Not before starting?

I don't want to push my luck with the gp especially as you said she's a keeper so I'd like to look for the test privately if I can.

The only neurological symptom I've got which I told her about was occasionally jumpy eyesight/difficulty focusing. Hard to explain, not quite double vision but jumpy especially when I look at something with straight lines like a radiator. But I know that can be from the hashimoto's too.

I have started with pins and needles in my thumb which I can't correct with posture (i'm a neurological physiotherapist) but she didn't know this.

I get the fogs, the mood swings, loss of labido and tiredness but again could be the hashi's. I do get the shortness of breath but didn't tell her that either. I forgot the majority of my symptoms when I was in there as there's just so many. I ended up telling her I've just been feeling generally crap for so long. So I'm only assuming she is treating off test scores?

Thanks for the advice. I was planning to start the folic acid tomorrow but I'll wait :) it will mean my prescription will run out in sync with the d3 then too. Thanks again x

1 like

IFA and PCA are two tests for pernicious anaemia. PCA isn't very accurate so not recommended as a test. IFA gives false negatives about 50% of the time so also not a very good test and a negative doesn't rule out the possibility of PA.

PA, however is only one absorption problem that will lead to a B12 deficiency - there are others and the treatment is the same assuming that it isn't an absorption problem that is easy to rectify (eg tapeworm - happens mainly in scandinavia).

to be honest I'd save your money and accept that you have an absorption problem. I would definitely broach the subject of neurological problems with her and the different schedule for loading doses - she's probably aware but isn't thinking neurological involvement at the moment.


sorry forgot to say - IFA can be done at any time as long as you leave it a week - 10 days since last supplementation. Supplementation can skew the results to give a false positive.

1 like

I don't mind not having a confirmation as long as I'm being treated which it seems lucky that I am being. If it's not going to make a difference to treatment then it's not a big thing for me I can accept that I've got some form of absorption issue. It was just because she said we can test for it at next blood test I thought it made a difference. I have a huge phobia of blood tests so would rather not :)

I won't be seeing her before starting the loading doses she has prescribed and the appointments are already booked in. Would it be an issue if I had this loading dose then if no change speaking to her about a different loading dose schedule? Or can you only have one loading dose?

It's going to be really hard to know which and what is causing what symptoms with the B12, D3 deficiency and hashi's all causing similar symptoms.

I'll just be happy to start feeling better rather than having a name for it :) thanks x

1 like

So glad you found a Gp who listens and more importantly is treating you.....


You may also like...