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Pernicious Anaemia Society
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Symptoms returning post loading doses

I just wondered if anyone else had experienced improved symptoms at the end of their loading doses (does 6) only for symptoms to return a week or so later?

I really thought I was making progress (3 days with drastically reduced symptoms) and then they all suddenly reappeared.

I’ve managed to convince my dr to give me another week of injections but I wondered if anyone else had experienced this?

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Bloods (if that helps)

B12 - 183

Folate - 6.5

Haemoglobin est - 150

MCV - 99

And antibody test says none present though my grandma has PA, however I am celiac.

Dr says she’s inclined to rule out a B12 def as bloods otherwise are in normal range and 183, “isn’t that low” and “shouldnt therefore cause neuro symptoms”


what were the units and ranges - 2 sets of units that can be used and have different ranges.

IFA gives false positives 40-60% of time depending on test method so a long way from ruling out PA.

Macrocytosis isn't present in 25% of people when they first present with B12 deficiency and macrocytosis isn't what causes neurological symptoms anyway. B12 is used by a lot of metabolic processes - the one that regulates the production of healthy red blood cells is very different from the processes that regulate nerve function.

Normal range misses 25% of people who are B12 deficient if taken as a single measure.

B12 levels aren't particularly useful after loading doses as some people react to highlevels of B12 in serum by trying to shut down the mechanism that allows B12 to pass from blood to cells. If levels are high enough then enough trickles through but as levels fall less and less gets through - leading to a functional B12 deficiency. Easiest way to treat this is to keep levels high. Net result is that normal range definitely doesn't apply after loading shots and on average levels over the top of the normal range need to be maintained for people to feel healthy.

At the other extreme some people manage to remove the B12 from their blood very quickly so levels drop very quickly.

Basic result is that you need to go on symptoms.

Are you UK based?

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Thanks for your reply Gambit62

I was starting to think I was going mad, the doctor was adamant that without Macrocytosis being present I couldn't be b12 def.

With regards to my results, apologies for not including the units and ranges, they are as follows,

B12 - 183ng/L (200 - 770ng/L)

Folate - 6.9ug/L (3.9 - 26.8ug/L)

Haemoglobin est - 150g/L (118 - 150g/L)

MCV - 90.5fL (80 - 100fL)

MCH - 31.2pg (28 - 33pg)

I requested a print out at the drs this morning, it differs slightly from what the dr wrote down yesterday so sorry for any confusion!

Your final paragraphs are really helpful! Do you know of any supporting evidence for this that I can give (or launch, at this point haha, at) my doctor? Sorry to be a bother!

Thank you again, Leanne :)

Oh and yes I am UK based


refer your GP to the BCSH guidelines on the diagnosis and treatment of cobalamin and folate deficiencies which they can access through the BNF but can also be found here


which is the source of the stats above. It also emphasises the importance of treating neurological symptoms and the regime is more aggressive - loading shots 3x weekly until symptoms stop improving followed by maintenance doses every two months - though even 2 months isn't enough for a lot of people.

You could also try pointing your GP at the area on the PAS website specifically aimed at helping GPs improve the diagnosis and treatment of B12 absorption problems


pernicious anaemia is an historical misnomer - the problem was first identified as a form of anaemia which lead to madness and death. This was 200 years before B12 was actually identified as the cause but there is still a lot of confusion with anaemia.

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Thank you, this is really helpful!


I felt exactly the same, after my 6 booster doses. I honestly felt my symptoms melt away. Less than a week later and they were, mostly, all back again.

I’ve been for 3, 3 monthly injections after since then and haven’t noticed any difference.

From what I can gather, from my experience as well as what I’ve heard and read, for a lot of people the 3 monthly injections just aren’t regular enough.

Obviously I am not a doctor, and this condition is fairly new to me as well, but if you have doubts about the frequency of your injections you should definitely bring it up with you GP, or even ask if a nurse could show you how to do them yourself so you don’t have to keep making trips to the clinic (I know how exhausting it can be when your symptoms are apparent).

Good luck on your journey though, wishing you the best!

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Thanks for your reply heather_turner it really helps to know Im not alone in this, though I hope you feel better soon.

I have an appointment with a neurologist on Friday so hopefully we can rule out anything else and I can march back to the doctors armed with all the info everyone has so helpfully provided :)

Either that or self injection, which is pretty scary!


I have just started self injections - it really is ok, just a bore. In my thigh it does not hurt.


Yes! Exactly the same & now still battling to get treatment.. good luck...

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Have you thought to join the Pernicious Anaemia Society? - click on the link below and scroll down


It costs £20 for one year's membership and it may be possible that they can intervene with your doctor on your behalf plus you have access to many informative articles.

I wish you well.


Hi LeanneMarie87

It is not uncommon for some symptoms to appear to get worse before they get better as the B12 starts repairing the damage done to your nervous system and your brain starts getting multiple messages from part of the body it had "forgotten about" or lost contact with.

I sometimes liken it to a badly tuned radio on which you have turned the volume up high trying to catch the programme you want when all of a sudden the signal comes in loud and clear and the blast nearly deafens you.

A lot will depend on the severity and longevity of your B12 deficiency as to how long before there is no further improvement or recovery.

Some symptoms will "disappear" quite quickly whereas others may take months or even years. There is no set timescale as we are all different.

If you can get to see a doctor please also ask him/her to check your Folate level as this and B12 help your iron to make red blood cells and to function properly

The British Society for Haematology guidelines say on the Diagnosis of B12 and Folate Deficiency "In the presence of discordance between the test result and strong clinical features of deficiency, treatment should not be delayed to avoid neurological impairment".


In other words despite your levels being "Normal" (I hate that word) your doctor should be treating you the patient and your neurological symptoms - not just looking at the computer screen.

I am not a medically trained person but I've had P.A. (a form of B12 deficiency) for more than 45 years.

I wish you well


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Thank you for your reply clivealive :)

The analogy about the radio is really helpful! The blast on Sunday evening was certainly almost deafening so this has helped calm me, thank you.

I think I was confused as I felt they were worsening and then all of a sudden I saw a huge improvement only for them to worsen again!

My folate came back as 6.9ug/l (3.9ug/l - 26ug/l range given) which the doctor has said is "normal" (that pesky word again) is there an ideal figure for proper b12 functionality? I started taking folic acid daily (400ug) in the meantime which I'm hoping will help.

Best, L

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the folate is a little low in range - because your body will start running a lot of processes that use both folate and B12 once you have had the injections this will mean that you will suddenly be using more folate - your bodies reserves of folate are very small so this means you can easily become deficient at this point. Best form of folate is from food but it might be a good idea to take a supplement as you have done.

I don't think there is really any such thing as an 'ideal' for anything related to B12 because people just vary so much.

If you do become folate deficient then that means the processes will stop running again so the symptoms of folate deficiency are pretty much the same as B12 deficiency.

If you have a problem absorbing B12 it is likely to affect other vitamins and minerals - particularly folate and iron.

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Yes, after loading doses, I went to one jab a week(for the past 8 mos) and now 2 jabs a week. After a few days, my symptoms start to come back. I think it's so important to treat the symptoms and not a one size fits all regimen.

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Thanks for your reply Wowo23, I definitely agree, b12 certainly seems like it isn't a one size fits all issue! Its madness that they treat seemingly random test results as opposed to the person :(


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