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Can b12 get worse even though I’m having injections every 3 months

B12issues profile image

So I have been having b12 injections every 3 months for 10 years now , however I can’t seem to last the full 3 months after a month I get externally exhausted really bad emotional outbursts and mood swings and generally feeling low I’m having a blood test Monday to see if anything has changed over the years could my iron levels be low or could the injection dose need to be increased or for me to have sooner

24 Replies

Your body is telling you. Try 2 monthly.

B12issues profile image
B12issues in reply to Nackapan

Yes I agree my body is telling me , I have brought this up with my GP in the past and they said I had to just have them every 3 months not much help really now it’s got really bad and effecting my mental health 😞

Nackapan profile image
Nackapan in reply to B12issues

Bnf have changed their guidelines to 2-3 monthly. Ask them to look

B12issues profile image
B12issues in reply to Nackapan

Thank you for your reply I will ask when I go in to discuss my blood results

B12issues profile image
B12issues in reply to Nackapan

I’ve also just recently had my b12 injection and usually perk up and symptoms get better almost straight away this time doesn’t even feel like I’ve had it

Nackapan profile image
Nackapan in reply to B12issues

That's happened to me . Disappointing.

Well I have had B12 injections monthly for years have just started weekly and I'm getting dummer and eyes playing up more basically body feels shot.I started SI weekly to see if I could actually get a lift out of b12 two weeks ago, still feel rubbish

Nackapan profile image
Nackapan in reply to Chucknz

J woukd get other things checked too on next blood test. Folate iron ect

I can’t go three months between injections. The one time I did, I became very ill and it took a long time to recover. I began weekly injections and felt worse at first, but eventually began to recover. You need to increase the frequency of injections to get better. With adequate frequency, you won’t have symptoms between injections and you won’t even feel like you need a shot. You will just feel normal. Good luck!

B12issues profile image
B12issues in reply to mcg-woo

Having my bloods done on Monday then will have a consultation with my GP hopefully we get sort something as I feel so bad

mcg-woo profile image
mcg-woo in reply to B12issues

Emphasize how bad you feel to your doctor and don’t give up. If your doctor doesn’t listen to you, then find one who will! Feel better soon!

B12issues profile image
B12issues in reply to mcg-woo

Thank you

Luac profile image
Luac in reply to B12issues

Please be aware that PA treatment should be symptom based and not related to the amount of B12 in your blood.

Your gp does not need to monitor your b12 levels as they cannot be used reliably in the uk. The nhs test cannot tell you how much of your b12 is active or inactive so even if you have loads of it, it could be mostly inactive and useless hence the deficiency symptoms.

There is no known toxicity from b12, this has been studied closely for decades. Plenty of gps and nurses are worried about 'too much' b12. That is not based on science and you should ask any doubting gp to show you evidence to the contrary.

Ask your gp to check the newest guidelines. These state that for neuerological symptoms you should get the injections more frequently - every 2 months on nhs. Dont let a gp decide if whether your symptoms are neurological enough or not, the guidelines are clear. Ask gp to read them to you if you are in doubt.

I self inject as i was not getting what i needed. I told my gp about it and got advice. It might seem scary at first, but the positive impact definitely outweighs the inconvenience. It can change your life. At least it might help you understand where your issues are coming from.

Id recommend a good multivitamin and miner to take daily with food and id be looking to improve acidity in your diet. These make sure you keep vit and mineral levels are as optimal as can be - these other deficiencies are not routinely checked but should be. That can be affecting your health too.

I take apple cider vinegar tablets and ive seen huge improvements in my bowel movements - this makes me hope im absorbing better.

I am on weekly shots. I've never heard of every 3 mos.

Really I’ve always been told by my GP 3 monthly

Ask them to check you for the Genitic mutation that causes your body to not be able to absorb b vitamins. Mthfr,is what it's called. I wasn't feeling better after weekly then monthly injections until I found a naturopath that found out this genetic mutation was why. I take methyl factors drops everyday along with a monthly b12 injection and it helped. Took about a month to notice. Good luck.

B12issues profile image
B12issues in reply to Vinnie77

Ok thank you so much and I can ask them tomorrow when I have my bloods taken? sorry havnt had my bloods done since I was first diagnosed with b12 deficiency 10 years ago so been a while , at first they were great is it possible to suddenly not be able to absorb them like I did I mean I noticed after the first few times I couldn’t last the 3 months but like I said on previous post the GP kept saying nothing they can do except offer me injections 3 monthly now it’s got to this stage which is so bad I don’t feel like I have had anything and had my jab Monday just gone usually feel better for a week then go downhill

in reply to B12issues

That's so mad. In america they seem to do an annual check up ...ten years is a long time and a lot can happen even in a year.

B12issues profile image
B12issues in reply to

Your telling me I had no idea what is was at first so didn’t know enough about it and stupidly didn’t ask the right questions

Yeah I recon even tho I have B12 regularly I,m getting much worse.

B12issues profile image
B12issues in reply to Chucknz

Have you told your GP

Hi B12issues,

I've assumed you're in UK.

Patterns of treatment for B12 deficiency vary from country to country and sometimes the type of b12 used in treatment can vary so it's helpful to know which country you are in.

A few links that may be helpful

If you have a PA diagnosis or suspect PA, have you considered joining and talking to PAS?

They can offer support and pass on useful information.

PAS (Pernicious Anaemia Society)

Based in Wales, UK.


There is a helpline number that PAS members can ring.

PAS have useful leaflets and articles that PAS members can print out.

Perhaps your GP would be interested in some of them?


Unhappy with Treatment (UK info)?

Letters to GPs about B12 deficiency

Point 1 is about under treatment of B12 deficiency with neurological symptoms.

Letters avoid face to face confrontation with GP and allow patient time to express their concerns effectively.

Best to keep letters as brief, to the point and polite as possible. It's harder to ignore a letter in my opinion.

Keep copies of any letters sent or received.

You could draw GPs attention in any letter to the increased risk of permanent neurological damage including damage to the spinal cord if a patient is untreated or under treated for B12 deficiency.

Neurological Consequences of B12 Deficiency

PAS news item


PAS article about SACD, sub acute combined degeneration of the spinal cord


Retention of UK medical records

There may not be evidence of a past diagnosis of PA (Pernicious Anaemia) or other cause of B12 deficiency in current medical records.

If you get proof of diagnosis eg positive test result/letter from specialist confirming diagnosis etc keep a copy in a safe place in case it's needed in the future.

Accessing Health Records (England)

CAB NHS Complaints

Local MP may be worth talking to if struggling to get adequate treatment

A few people go to the press although this may impact on the GP/patient relationship.

Newspaper article about patient struggling to get B12 treatment in Scotland

And a positive follow up story

UK B12 documents

BSH Cobalamin and Folate Guidelines

Summary of above document


BMJ B12 article

Emphasises need to treat patients who are symptomatic even if their B12 level is within range.

BNF Cyanocobalamin

BNF Hydroxycobalamin

See section in above link for those with "neurological involvement" if you have neuro symptoms.

NICE CKS B12 deficiency and Folate deficiency

Each CCG/Health Board/ NHS Hospital Trust will have their own local guidelines on treatment/diagnosis of B12 deficiency. You could track down the local guidelines for your area of UK and compare them with BSH, BNF and NICE CKS links above.

Neuro Symptoms

If you have neuro symptoms, I would expect you to be on the second treatment pattern outlined below. GP can find this info in their BNF book Chapter 9 Section 1.2 or in online BNF.

1) UK recommended treatment pattern for B12 deficiency without neuro symptoms is ...

6 B12 loading jabs over 2 weeks followed by a jab every 2 or 3 months

2) UK recommended treatment pattern for B12 deficiency WITH neuro symptoms is ...

A B12 loading jab every other day for as long as symptoms continue to get better then a jab every 2 months.

The every other day loading injections could go on for weeks even months as long as symptoms continue to improve.

If your symptoms are deteriorating, perhaps your GP would consider giving you another set of loading doses?

Might be worth keeping a daily symptoms diary that tracks howe your symptoms change and if and when treatment is received. Can be useful evidence to show GP.

Sometimes patients may need to assertive with GPs to get appropriate treatment although some GPs do no respond well to patients asking questions and challenging their decisions.

Over the years I have been surprised at the level of ignorance about B12 deficiency among some health professionals. Some GPs and specialists have misconceptions about B12 deficiency.

B12 article from Mayo Clinic in US

Table 1 in above article is about frequent misconceptions about B12 deficiency.

I've written some very detailed replies with more B12 info eg more B12 articles, b12 websites, B12 books etc in threads below.

I am not medically trained.

Hi thank you so much for your detailed reply so much information I’m just trying to digest it all ! Yes I live in the uk

It’s hard as like I said at the beginning things were fine although it did take nagging the doctor at first before being finally diagnosed with b12 deficiency. I’m having my bloods done tomorrow and then they suggest I talk with my GP about the results ,

I’m so worried that they will just palm me off with anxiety and depression and not look into my b12 and iron levels my body’s is definitely telling me something isn’t quite right also worried I will forget to ask the right questions

There have been some UK forum members who have had their B12 levels tested long after treatment has started and their injections have been stopped because their B12 levels are above the normal range and their GP has some misconceptions about B12 deficiency.

PA requires life long treatment. There is a PAS leaflet "Treatment is for Life".


There are other causes of B12 deficiency that require life long treatment.

My understanding (I'm not medically trained)is that B12 levels are likely to be high (above range)if on regular injections.

See articles below.

Testing B12 during treatment (PAS article)


Above article has some useful quotes from UK B12 documents and may be worth passing to GP.

Testing B12 during treatment (English article from Dutch b12 website)

Units and reference ranges may vary from those used in UK.

Misconceptions about a B12 deficiency(English article from Dutch b12 website)

Treatment with high dose vitamin B12 been shown to be safe for more than 50 years

(English article from Dutch b12 website)

Look at table 1 in article below about misconceptions

B12 article from Mayo Clinic in US.

Above article suggests ....

1) No proof that oral b12 is a good at treating B12 deficiency as B12 injections

2) Many current tests eg serum b12, active B12, MMA, Homocysteine, are not totally effective as diagnostic tests for B12 deficiency.

3) Successful treatment should not be stopped

"also worried I will forget to ask the right questions "

Why don't you write out a list of questions before your appointment and take it with you?

Is GP going to test your folate levels and iron and full blood count (FBC)?

I hope you find your appointment helpful.

If you're a PAS member, you may find it helpful to call their helpline before your appointment. They can offer support and info.


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