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Pernicious Anaemia Society
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LowB12 and iron

Hi I was diagnosed with low B12 in July 175 and low haemoglobin 10 and ferritin 7 then 4 week later 2nd blood test B12 was 152. Had loading injections and iron tablets then 7 weeks later had blood test told levels nice and high now no further action. After reading most people once low B12 need it for life so saw GP who said blood test every three months for a year then every 6 months as could be one off. I had all the symptoms prior to B12 fatigue, extreme tiredness, pins and needles, forgetful and feeling confused and I don't want to feel like that again. Is my GP right to only give me B12 if it drops right down again? Thanks in advance

16 Replies

No! Low b12 and iron reeks of h pylori infection. Please demand to get tested.

And if that isnt positive ask what did cause it. The root issue needs to be at least looked for and if cannot be determined injection for life are likely needed.

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Thank you for your reply I will mention to my GP. My GP has implied it is my diet he kept asking me if i had a restricted diet but i said no i eat all food groups and he has advised me to increase b12 rich foods in my diet but there is only so much I can increase by as I am a meat eater and I eat fairly health meals.


Hi mesadies a lot will depend on the cause of the B12 deficiency and whether it has been remedied.

Anyone at any age, can become B12 deficient. However, certain people are at an elevated risk. They include the following:

Vegetarians, vegans and people eating macrobiotic diets.

People aged sixty and over

People who’ve undergone any gastric and/or intestinal surgery, including bariatric surgery for weight loss purposes (Gastric bypass).

People who regularly use proton-pump- inhibitors. H2 blockers, antacids, Metformin, and related diabetes drugs, or other medications that can interfere with B12 absorption.

People who undergo surgeries or dental procedures involving nitrous oxide, or who use the drug recreationally.

People with a history of eating disorders (anorexia or bulimia).

People with a history of alcoholism.

People with a family history of pernicious anaemia.

People diagnosed with anaemia (including iron deficiency anaemia, sickle cell anaemia and thalassaemia).

People with Crohn’s disease, irritable bowel syndrome, gluten enteropathy (celiac disease), or any other disease that cause malabsorption of nutrients.

People with autoimmune disorders (especially thyroid disorders such as Hashimoto’s thyroiditis and Grave’s disease) Type 1 diabetes, vitiligo, lupus, Addison’s disease, ulcerative colitis, infertility, acquired agammaglobulinemia, or a family history of these disorders.

Women with a history of infertility or multiple miscarriages.

Do you see yourself among any of the above "people"?

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Thank you your reply I do have an under active thyroid and I have had IBS for about 25 years also I have had iron deficiency anaemia on and off for last few years


Your GP is wrong to treat you based on serum B12 levels.

The test can be useful in diagnosing an absorption problem but once treatment has started it is no longer a useful guide as it doesn't tell you what is going on at the cell level, and the shots themselves can have an impact on the mechanism that allows B12 to move from blood into cells so normal range for serum B12 no longer applies.

If you are UK based you should point your GP at the BCSH guidelines on diagnosis and treatment of cobalamin and folate deficiencies which your GP can find on the BNF but can also be found here if you are UK based


different guidelines apply in other countries but if you are based outside the UK then this articles might be of use


you can also find references to other articles in the pinned posts.

You could also try pointing your GP at this area of the PAS website particularly targeted at health professionals and helping them to treat their patients better



Thank you for your reply I am UK based and I feel my GP is just trying to save money on injections which if I don't need them then that is fair enough but I am hoping if my next blood test shows a drop in B12 that I will need to have follow up B12 injections or I guess if they don't drop my symptoms won't return or am I being naive?


to reiterate- serum B12 levels are not a good guide to what is happening after loading shots and should not be used as a way of determining if you need another shot - you need to follow your symptoms.

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Yes I think I might start keeping a log of them as pins and needles are already returning in my right foot plus mixing up my words. I looked at buying some vitamin B12 tablets but I am not going to find out if I have stopped absorbing B12 until a couple more blood tests I guess. It's all such a minefield.


I have just read UK based information and I do take thyroxine for under active thyroid so maybe this caused my anaemia


Re. blood tests, you could write or show GP the latest BMJ research document summary - GP should be able to access the full document, which is behind a paywall - here is what it says on page 4 under: 'How is response to treatment assessed? ' :


"Cobalamin and holotranscobalamin levels are not helpful because they increase with vitamin B12 influx regardless of the effectiveness of treatment, and retesting is not normally required."


Under: Parenteral treatment

"Standard initial treatment for patients without neurological involvement is 1000 μg intramuscularly three times a week for two weeks.

*If there are neurological symptoms then 1000 μg intramuscularly on alternate days should be continued for up to three weeks or until there is no further improvement.4 25 In irreversible cases, for example, pernicious anaemia, the treatment should be continued for life."


Your original test result was very low and may also find the information in the following link helpful in deciding what to do next. If GP is still unco-operative, you could contact the PA Society to support your case for more frequent injections.



I notice that you also have thyroid disease which can also be linked to other autoimmune diseases and PA, due to gastric atrophy or, as KimberinUS has suggested, H/pylori.

The little book, 'Understanding Thyroid Disorders', written by Dr Toft, is published in association with the BMJ, and I found it helpful to show GP to ensure an optimum level of thyroid medication:

"Typical results would be a fT of 24 pmol/l or TT4 of 140 nmol/l, and a TSH of 0.2 mU/l. In some patients, a sense of well being is achieved only when fT4 or TT4 is raised, for example 30 pmol/l or 170 nmol/1 and TSH low or undetectable. In this circumstance, it is essential that the T3 level in the blood is unequivocally normal in order to avoid hyperthyroidism."


It’s a good thing your GP is giving you 3monthly blood tests.

Mine sticks to 1 per year and says he’s not allowed to do more.

I’m not an expert but maybe he’s trying to find the cause, so in your next blood test if your level ‘drops’ that indicates you have an absorbtion problem.

So after 2 blood tests (6 months) if your levels have further dropped I think that will confirm your problem.

It’s true after injections numbers don’t matter, symptoms do. So I think if you carry on injecting you won’t know you have an absorbtion problem.

I’m no expert and could be wrong , but maybe he wants to know how much it drops after each blood test ! Which is a good way of knowing you have a definite problem.

If he’s/she’s giving you 4 blood tests in 12 months he might be doing the right thing. It makes sense to me, but there’s people on this site who know much better.

Depends on how bad your symptoms are and if you’re able to wait for what the blood readings will be for the next 4 tests.

I would personally wait for at least the next 2 tests to confirm levels are dropping.

Sounds like a good doc to me!

Wish you well.


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Thank you that is a lovely positive reply and yes hopefully further blood tests may give a better picture of what's going on if anything


I think you all need to pay attention to clivealive

"a lot will depend on the cause of the B12 deficiency and whether it has been remedied.

Anyone at any age, can become B12 deficient."

The problem with the guys on this forum is that you are all so quick to jump on the "omg you need B12 for life, you need to insist they go by the guidelines" when this person could have been deficient for a couple of months and is now actually OK, yes they may still have symptoms, but it does not necessarily mean they are down to B12.

Just because B12 is not dangerous, and excess is pee'd out, I feel it should still not be handed out like sweeties to everyone who has a slight symptom.

There are MANY reasons for the symptoms that this site lists. I feel that sometimes people get answers on here like "omg get B12 for life" so they stop looking for other reasons. What if they are NOT actually B12 deficient?

I know this all sounds awful, but my B12 deficiency was found as they were ruling everything else out.

If you all keep telling people to get on the B12 and that's it, then so many people are going to be badly diagnosed.

Just because someone had a bad result once, it does not automatically qualify them as having any kind of B12 deficiency.

I was pregnant twice, doesn't mean that every time I get a contraction in my abdomen that I'm about to give birth.

I broke my ankle twice (exactly the same way actually which the surgeon said was a miracle to do once, never mind twice) doesn't mean every time I go over on my ankle and it hurts like hell, that I've broken it again.

I understand that you are all trying to protect these guys, but you are not getting the full facts and history from all of them before you preach about B12 for life and so on.

I would hate to tell someone that they have a deficiency so they stop going for tests as they now know what it is, and it turns out it's MS. (the symptoms are identical because in many ways it IS identical, especially if lack of B12 has caused damage so much that lesions have formed on the brain/spine)

I am really sorry if you think I'm being awful. I'm just trying to be realistic here. I see it with every single new person that asks about B12, the immediate reaction is "OMG your level is low so you need injections for life" that is possibly not the case in a LOT of the people who post for the very first time after having 1 or 2 low results.

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Hi so it's been a while since I have been on here and I keep getting strange clusters of tiny dot like bruises appearing. Does anyone else get these? I would load a picture but not sure how to load one on here. I am due to have another blood test in January as doctor still adamant my levels were high after loading injections so no need for more b12. I think it has been about 18 weeks now since having them


You need to start a new post with your information above as it will not be noticed this far down in the thread. I spotted it in the News Feed !

Regarding your thyroid treatment - do you have Hashimotos ? - do you have the latest thyroid test results with ranges ? - what dose of Levo are you on ?

I have been on the Thyroid Forum here on HU for over 6 years and would suggest you pop across and have a read. It is well acknowledged that having Hashimotos trashes the absorption of nutrients resulting in low levels of B12 - Folate - Ferritin and VitD. All need to be optimal for thyroid hormones to work well in the body - your own and the ones you swallow.

Sadly your GP is lacking in knowledge - of course your levels will be high as you had a B12 injection - sigh .... Testing once supplementing is of little use and this is mentioned in the Guidelines your GP should have read.

I have Hashimotos - a B12 issue and inject weekly - and Crohns - so have had to learn lots among the hedgerows of life.

Happy to help :-)


Hi thanks for reply. I was diagnosed with under active thyroid six years ago. I am on 100mg of thyroxine and I am told it is well controlled at 3.4. I will have a look at the thyroid forum thanks for your help


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