A bizarre and wasteful practice – Is your doctor following this crowd?

Jun 20, 2019 | Serum B12 test | 22 comments

It seems there are a group of doctors using the B12 test to in order to remove B12 injections from patients who require life long treatment.

I have blogged about this practice before but due to the extra impact it’s having I thought it time to revisit.

Some doctors (far too many) are systematically re testing serum B12 levels in those already diagnosed believing that a ‘within range’ result means the patient can function without their essential treatment.

These patients cannot absorb B12 from food, hence their original diagnoses, so how exactly are they meant to access B12 without their injections?Test shortage
Another impact of patients being retested unnecessarily is a resulting lack of the reagent required to carry out the test. This has happened in the past few months and obviously delays diagnosis and treatment for new patients.

Wasteful and harmful
This practice is nearly always wasteful but it’s harmful to the patient too if the doctor fails to understand that testing once the patient is on treatment is useless and that the result has no relationship to the level of B12 in their cells.

What the experts say
The testing lab often add this note to the bottom of a high result; “Do not measure B12 levels in patients who are on parenteral treatment”

and to quote NICE Guidance;

  • Measuring cobalamin levels is unhelpful as levels increase with treatment regardless of how effective it is, and retesting is not usually required.
  • What monitoring is required after treatment for vitamin B12 or folate deficiency has started?

    • Perform a full blood count and reticulocyte count: 

    • Within 7–10 days of starting treatment.

    • A rise in the haemoglobin level and an increase in the reticulocyte count to above the     normal range indicates that treatment is having a positive effect.

    • If there is no improvement, check serum folate level (if this has not been done already).

    • After 8 weeks of treatment, and also measure iron and folate levels.

    • The mean cell volume (MCV) should have normalised.

    • On completion of folic acid treatment to confirm a response.

    • Measuring cobalamin levels is unhelpful as levels increase with treatment regardless of how effective it is, and retesting is not usually required.

    • However, cobalamin can be measured 1–2 months after starting treatment if there is no response.

    • Neurological recovery may take some time — improvement begins within one week and complete resolution usually occurs between six weeks and three months.

    • Ongoing monitoring is unnecessary unless a lack of compliance with treatment is suspected, anaemia recurs, or neurological symptoms do not improve or progress.

Remember if you are neurologically affected you need to be on every other day injections for as long as it takes for those symptoms to stop improving.
Best wishes


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  1. Donna smith

    Can I print this page off please to take to my gp x

    • Tracey Witty

      Hi Donna, for some odd reason I can’t make it printable but I will email the text to you. Best wishes

  2. Nic

    Would be helpful to have guidelines for USA also please

    • Tracey Witty

      I don’t know of any USA wide B12 guidelines I’m afraid.

    • Pauline

      Could I have this info please

  3. Kathy skafidas

    My son had extreme depression ocd school withdrawal quick onset. Found to be low zinc and b12 low d and mag. Will he have to supplement for life? He is ten

  4. Withheld for pt confidentiality

    Last summer my father-in-law, who has dementia related to the failure of his GP to diagnose his B12 deficiency for over 5 years, had his injections changed from every 2 months to every 3 months, on the whim of the practice nurse. As it was on 2 monthly injections his symptoms became worse in the week before his injection was due. He subsequently had to be admitted to hospital, stayed for 6 days, returned home with a hospital acquired pneumonia, was re-admitted for 10 days and due to the hospital junior pharmacist reading the BNF remains on 2 monthly injections. We have now bypassed the incompetent clinicians and he has weekly methylcobalamin patches in addition to the 2 monthly injections and he is much improved! The saving to the NHS of reducing the frequency of his injections was minimal. The cost of his hospital admissions must have been very significant!

  5. Hayley

    I am unsure at the moment where I stand. I am meant to be having a blood test and then communication with GP regarding injections. My b12 result was below guidelines. I had a trial if b12 injections. I changed surgeries and think have got lost in the system. I am currently buying my own ampules and self injecting else I wouldn’t be able to function. If I do not self inject I become breathless, lose my memory, have tinnitus and become to weak to walk. I have 3 children and card for them alone. If I could buy ampules over the counter it would be a life saver
    Thank you Tracey

  6. Anne Crotty

    My B12 injections were stopped for a year and, although I managed to get them restarted, I still haven’t recovered. I have been prescribed 3-monthly injections as before but only for 5 ampoules. They take ages to kick in and I feel I need the next one long before it is due. I try to have a discussion about the useless blood tests but to no avail. I will probably have to have a tussle when they have been used. Heaven knows whether I can even see a GP with the present crisis as my blood levels are “normal”!!!

  7. Anon Kent

    I was diagnosed with Vitamin B12 deficiency a year ago after months of thinking I was losing my mind. Dizzy spells, depression, forgetfulness, palpitations, losing my hair amongst other things. Had course of injections then put on 3 monthly ones. After about 6 months the injections started sto wear off at about 7-8 weeks so all symptoms returned. After going to GP and seeing 2 different ones who just kept asking if I wanted antidepressants. I said I am depressed because of lack of B12 and didn’t want antidepressants. They agreed to change to 10 weekly. 6 months later I find I am still desperate at about 7-8 weeks and am scared to drive for those last 2-3 weeks whilst waiting for injection. Begged GP last week to do it 2 weeks early given that we could be on lockdown soon. They said no and ordered blood tests which came back normal. As blood count only shows B12 levels and not actual amount body can use. Now have 2 kids to homeschool while not even being able to stand up for more than 5 mins because room is spinning. Why are they being so difficult about doing it 8 weekly instead of 10?

  8. Sarah

    I went for my b12 injections but was told I no longer needed them even though there were no recent blood tests. after discussing this with the gp it was agreed to give me a b12 injection this time but would take bloods first. a week later I was told I just needed to take over the counter b12 iron folate and ferritin and injection not required.
    I have shown my results to a gastroenterologist who says I need the injections for life but as I’m not a patient he can’t write to my gp.
    stuck in the middle

  9. Rachael.M

    I have just been diagnosed with B12 deficiency in February 2020. It has taken over 9 months of investigations for my b12 level to drop to “deficient” as before this I was taking high dose oral b12 supplements which neither my GP or I realised were skewing my real results and they were considered “low normal”. During this time my symptoms were getting worse, extreme fatigue, insomnia, depression, anxiety, neurological symptoms – twitching muscles, pins & needles amongst a host of others. I have now had loading doses via my GP and will continue 8 weekly. All of my symptoms have greatly improved, However I have had to start self injecting with supplies from a German pharmacy as my consultant & GP won’t follow BNF advice to continue with every other day injections until neurological symptoms STOP improving. Only thanks to sites like this and the Facebook b12 support groups, have I got the correct information to help me fight for treatment and guide me to self treat appropriately. Thank you so much for all you do!

    • Tracey Witty

      Rachael, I am so please you are on the road to recovery, thank you for your comment. Best wishes Tracey

  10. Flo

    I was first diagnosed with b12 deficiency just under 10 years ago now. In that time I have had 3 sets of loading doses and never given regular injections…only retested my blood which ofcourse came back normal until the next time I fell below range. This last time I was below range they refused loading doses and insisted on retesting my bloods in 3 months even though my level was 157. I was given one single jab because of myself crying and begging the Gp due to my symptoms which of course brought my next bloods barely but in range. 5 years ago I went partially blind due to a combination of blood clots in my right eye. I was sent away being told I’m a medical mystery and put on aspirin for life. Since then studies have been done with the link of b12 and vit D deficiency and these occlusions finding a rise of cases in younger people. I was 28 at the time. I truly believe due to the mismanagement of my deficiency this happened. Also since that they even point blank refused to test my vit D so I didn’t find out how deficient I was until paying privately this year which my levels reflect how long I’ve been deficient. All in all I’ve been told all the excuses and schpiel GPs reel off. Sent for tests which were just symptoms of B12 deficiency and just point blanked refused essential treatment. Now I have given up and going to try and self treat, in the current climate self injection isnt an option so sublinguals or spray will have to suffice. It has definitely spread across my county how they are cracking down on nursing hours and even those on injections are being switched to tablets or those newly diagnosed put straight on to tablets. It’s a dangerous game especially when this simple vitamin can cause so much damage. Something needs to change…

  11. Hayley

    After questioning my appointment for B12 injection being cancelled due to Coronavirus, my GP surgery have now decided there is no evidence in my records for me needing B12 injections and will no longer provide me with it. I was denied my injection once before and it took a change of GP surgery and a year of watching my levels drop with each blood test to get them reinstated. I know the rest for Pernicious Anaemia came back negative and I believe this is why they are stopping my injections.

    I feel I need these injections as everytime I have one symptoms such as fatigue, breathlessness, tingling, IBS, pain & anxiety reduce and pretty much disappear until about 10 weeks after the injection when they begin to come back until the injection is given at 12 weeks.

    I now feel I have no choice but to source my own supplies and self-inject, especially with the current situation. I am in shock I am yet again been treated so badly by doctors.

    • Tracey Witty

      This is appalling Hayley and should be challenged. The fact that you have not tested positive for PA is totally irrelevant – you are B12 deficient, you cannot absorb B12 from food and that is why you have been prescribed B12 injections.You have neurological symptoms so it is vital that you have regular B12 injections. Your Practice are behaving irresponsibly, they could supply the ampoules to you and the equipment to self inject as other Practices are doing. Can you email this comment and response to your Practice? Best wishes Tracey

    • Zoe Rimmer

      Hi Hayley, I’m the safe. Ironically a couple of years ago, the same GP agreed to give me the injections every 10 weeks because of symptoms coming back. On 12 weekly injections I had a lot of angular chellitis (sore cracks in corner of mouth). Having it 10 weekly was better.

  12. Zoe Rimmer

    My GP practise text and cancelled my B12 injection blaming Covid 19.

    I have multiple serious health conditions, including a serious heart condition, spinal cord damage from herniated discs and Adhesive Arachnoiditis (Degenerative Lumbar Disease) triggered by Ehlers Danlos.

    I rang to ask what alternative options there were, to be told I would have enough in my system to last at least 6 months and the surgery was closed to all patients at that time, and ring back.
    I rang again the following 2 weeks to see if there were any changes, and asked about self administration. The response I got was ‘Dr says it’s too dangerous to self inject because of possible adverse reactions.’

    I decided to escalate my complaint to the local health board at this point.

    Next my GP called and announced he had decided to withdraw all my B12 treatment based on my levels currently being in the normal range. I can have blood tests 3-6 monthly if I want and wait until the levels drop below normal, then he *might* reconsider treatment.
    He used the fact my IF antibody blood test was negative, in 2010 and said this will never change. He said I was incorrectly diagnosed and had been incorrectly receiving B12!
    I had to correct him about the antibody test, so he will now include an IF blood test as a one off.

    He then disregarded B12 absorbency issues and all the various medical reasons that would personally be preventing me absorbing B12 orally.

    I’ve been on PPI long term and still am, this is for acid reflux and mild gastritis due to Ehlers Danlos Hypermobility and the GI involvement EDS brings. This alone is enough for many patients to have B12 absorbing issues and need injections to replace intramuscular.
    I also have Hashimotos Thyroiditis, which is also know to cause inflammation of the gut and inhibits absortion of B12.
    Hashimotos Antibodies also affect the immune system and can be the cause of other autoimmune conditions. I have not had a test for Anti Paretial Antibodies.
    I have recently learnt I’m glutten intolerant through another GP, after many many years of embarrassing GI / incontience issues with full collapse in the bathroom. (Much worse than IBS)
    I also have systemic thrush, and cannot take routine treatment for this, because of a serious cardiac condition.

    I usually take a vitamin B100 from Holland and Barrett which includes a 4000% RDA of Oral B12, which is for the benefit of all the rest of the B vitamins.

    My GP refuses to believe my current symptoms are anything to do with my B12 injection being overdue, and insists on me getting blood tests, which I cannot do. Unfortunately I am on 12 week self isolation / shielding group due to Covid 19 and blood tests have to wait. Breaking this isolation puts my health at other serious risks. Not getting B12 puts my immune system at serious risk.

    It feels like he’s chosen to stop all treatment in spiteful reaction to my complaint to the local health board. Either way, it is to the same effect of those going without an injection for 6 months, except I have to go the extra mile of suffering and getting a below range blood test and suffer the ill health and risks that brings of permenant neurological damage. I already suffer with small fibre neuropathy.

    I joined the PA Facebook group, which has been full of helpful information.
    I used the brilliant template letters to write to my GP, which he completely ignored. I raised this complaint to my local health board who honestly, have been just as unhelpful.
    They simply suggested to the GP that high strength B12 tablets might be a helpful alternative! There is no medical evidence or trials proving the effectiveness of this.

    When I was originally diagnosed, a long time a ago, I remember being extremely short of breath, very tired, having a sore tongue with circular ulcers on the tongue, Raynauds, burning hot legs and feet at night. I had a range of blood tests done and I was told I needed the B12 loading injections and then an injection for life every 12 weeks.

    I am worried they will try this with Thyroid treatment next.

    I was under an Endocrinologist at the time, but I think it was my old GP who diagnosed and started the treatment. I can’t be sure, but one of them did the IF blood test which was negative, but told me the tests are not very reliable and only part of the investigation. I also have family who have suffered with long term acid reflux and gastritis leading to stomach cancer and wonder if it could actually be hereditary PA.

    I can’t believe GP surgeries are being allowed to play God and are going against all current NICE and WHO guidelines, and the total disregard to current BMA-and RCGP guidelines, beggars belief. Covid 19 is an ideal to sneak in health system changes like this and blaming the virus for this.

    I felt I had no alternative option but to purchase the necessary kit to SI myself, but the downside to this is, if I do SI, the blood tests will always be in a normal range and my GP won’t give the treatment I’m entitled to.

    My other choice is dreadful. It is to do nothing, stop my B100 altogether and too and wait until I am gravely I’ll again, this is cruelty and I shouldnt have re-prove this to my GP all over again. How many times in the future will I have to go through this?

    He stated the normal range for our area is between 150-1500. My lowest blood test was below 130 when I was diagnosed, and on treatment it varies between 350-600. I am not being over replaced. The NICE guidelines suggests anyone with levels under 200 are considered to be low and at risk.

    I have also had an increase in heart rhythm disturbance towards the due date of my B12 injection. I have recorded multiple episodes on my Apple Watch and have quantifed this to him. I have had to double my heart medication already. My local cardiologist is aware I am overdue and my levels will be lower, and wants the B12 injection to go ahead and then see how things improve.

    Many years ago however, I had asked my electrophysiology cardiologist (EP) at a specialist hospital, if having B12 injection can trigger palpitation (the opposite) and he said no. He said the B12 was fine for my heart and good for my blood and nervous system.

    (I’d had B12 and a flu jab on the same day and it landed me in hospital needing DC cardioversion.)

    My GP used this letter against me, saying the EP state’s B12 doesn’t have anything to do with the heart!

    I have never seen a Haematologist, despite my Folate and Ferritin and White Blood Cells being low range, my sister has cancer of the blood, and a genetic alteration, and I believe I should see a haematologist next. I didn’t know it was necessary until joining the Facebook group.

    I have written our local AM, MP and the Health Minister for Wales. I have no idea how long it will take to hear back from the, and hope this information helps you.x

  13. Lee

    My doctor categorically stated that I would receive no benefit from injections and refused to provide them. When I returned, he laughed in my face and told me I was wasting money when I said I had been paying to receive them privately and advised me that my alleviation of symptoms that had lasted 20 plus years (fatigue mostly but also muscle pain, stomach issues including heartburn and constipation, low blood pressure, dizziness upon standing, hair loss and latterly numbness in my right foot and hand) was due to a placebo effect. I paid privately for the b12 and active b12 tests which were ignored by both the private doctor and nhs doctor as ‘in range’ at 226 pg/ml (I had already started supplementing before tests which I believe may have skewed the results). Since I can no longer source private injections owing to Corona virus I have resorted to self injection and am too scared to advise my GP of this.

    • Tracey Witty

      As we know Lee, your GP has an awful lot to learn. I hope that at some time you will feel well enough to tell your GP that in the absence of any care or understanding from him, that you have kept yourself alive by sourcing the B12 you need.
      I wish you all the very best, Tracey

      • Lee

        Thank you and thank you for the information you are sharing. I’m so glad I didn’t wait to start treatment.

  14. patricia morris

    After reading the comments, I am very lucky to have a great GP.
    Got my latest injection yesterday, told them how I was feeling after 8 weeks post injection. Today they have agreed I can have my next injection after 8 weeks.


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