Help interpreting B12/blood test resu... - Pernicious Anaemi...

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Help interpreting B12/blood test results?

Gilly27 profile image

Hi everyone, newbie here.

I had a blood test a wee while ago due to fatigue and feeling generally run down and lethargic for a long time. I wanted to rule out thyroid issues but the Dr called me to say I had a B12 deficiency (135ng/l) and prescribed me 5 loading dose injections over two weeks to be followed by a top-up injection every 3 months. After 4 of the first 5 injections, I was still feeling pretty tired so he prescribed me an aural iron supplement which I have been taking for a couple days now (my ferritin level was 22ug/l).

I was quite keen to try and get to the route of the issue because I eat quite a lot of meat and dairy so the deficiency didn't seem to be diet-related. They've tested my intrinsic factor levels, my anti-gastric parietal cell antibodies as well as a test for Coeliac Disease. Everything came back negative/normal. I was originally told that they would refer me to a gastroenterologist if these tests failed to explain the underlying problem but, today, a different Dr basically told me the line ends here and that 'lots of people are tired without knowing why'... He even suggested that my B12 level may not even be an issue because 'the test isn't that reliable' which makes me worry that they aren't going to continue the shots.

Can anyone enlighten me as to what to do/pursue in this situation? Do I push for further tests/a referral or do I just accept that I may feel run down and crappy for the foreseeable future with no real answers? :/ (A third alternative is also welcome..)

Thank you!

ps here is the rundown of my blood test results just incase this clarifies anything for anybody:

16 Replies
clivealive profile image
clivealiveForum Support

Hi Gilly27 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" in any of the above people?

If you do have thyroid problems that will put you at risk as highlighted.

If you are in the UK it appears that your doctor is treating you in accordance with the N.I.C.E guidelines for a Vitamin B12 deficiency but your Folate is also at the low end of "Normal" and you don't mention that he has prescribed folic acid for that. It would probably be a good idea to buy Folic Acid 400μg tablets over the counter at your local chemist and take one a day - either that or increase your intake of leafy green vegetables, sprouts, broccoli, spinach, asparagus, beans, peas etc.

There is a complex interaction between folic acid, vitamin B12 and iron. A deficiency of one may be "masked" by excess of another so the three must always be in balance.

Folic acid is crucial for proper brain functioning and plays an important role in mental and emotional health and works closely with vitamin B12 in making red blood cells and helps iron function properly in the body.

As for feeling "run down and crappy for the foreseeable future" it is not uncommon for some symptoms of a B12 deficiency to appear to get worse before they get better as the B12 starts repairing the damage done to your nervous system. A lot will depend on how long you have been deficient and although some symptoms may "disappear" quite quickly others may take many months.

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

I wish you well

Gilly27 profile image
Gilly27 in reply to clivealive

Thank you for your reply.

Looking at the above list, I actually don't fall into any of those categorise :/ It's why I'm so confused as to why my iron and B12 levels were so low in the first place. I was pleased when one Dr said I would be referred to a gastro-entirologist for further testing (who doesn't want answers to why they're feeling unwell) so I'm obviously now quite disappointed that another Dr is telling me there's nothing more to be done.

I hadn't heard about symptoms seemingly getting worse before they get better so I'll bear that in mind.

I asked about folic acid and he didn't seem to think my current levels were an issue but I have certainly read otherwise. I will look into the over the counter option, thank you. I do feel a bit overwhelmed by the number of prescription and non-prescription meds/supplements I'm taking at the moment...but I guess one more can't hurt!?

clivealive profile image
clivealiveForum Support in reply to Gilly27

You should see my list of medications... well perhaps not :)

Moses was told to "keep taking the tablets" and he lived for 120 years...

A1Sparkle profile image
A1Sparkle in reply to clivealive


Yes , as the doctor said the B12 serum test isn't reliable , and we know that up to 80% of the B12 reading can be inactive B12 i.e. our bodies cannot make use of it . So you can appear to have a sufficient amount but be deficient . Yes, lots of people can be tired without knowing why, as the doc said ,but our doctors should try to find out the reason. That's what they are trained for . If you are continually below par because of fatigue , you are more vulnerable to other diseases. The Intrinsic Factor and the parietal cell antibodies test are also unreliable . The doctor has to become more of a detective to track down causes .

Look if I were you I would consider self injection of B12.. whatever ..... it is absolutely 100% harmless . I was really fearful when I started 2 years ago. It has changed my life. I had proven P.A. but could only get one injection every 3 months ., which kept me feeling really ill . Don't forget you need folate /folic acid to act with B12.

Get back to us if you want to go down the S.I. path.

Gilly27 profile image
Gilly27 in reply to wedgewood

Thanks wedgewood! I had heard that testing total serum B12 levels can mask a deficiency as it can't differentiate between active and inactive B12 - but that would imply that the levels were in the normal range to begin with. Mine are already deficient but the Dr said it could be bogus - is a 'false negative' like this possible or likely do you think? His comments have made me worry that he doesn't intend to continue with the B12 shots at all.

I admit, the thought of self-injection really scares the c**p out of me at this stage..but if my symptoms persist (fatigue, headaches, brain fog, memory issues) I guess it's something I'll have to consider!

I take 40mg/day of Citalopram for depression/anxiety and have done for many years. After reading that psychological issues can actually be a symptom of B12 deficiency, I asked a Dr about this and he said this wasn't related. I only mention this because the NICE guidelines say that any neurological symptoms ought to be treated more aggressively, with more frequent B12 shots? Maybe I'm grasping at straws for a 'cure-all' situation, but I am just becoming so tired of the Dr completely dismissing everything that I've read about B12 deficiency.

The reason that the PAS formed was because of the medical profession's failure to understand the problems and realise how many can be solved with a simple B12 injection and sufficient folate / folic acid . We have to thank Martyn Hooper for that . Of course psychological and neurological problems can be related to B12 deficiency . I have read so often that doctors have fobbed off B12 deficient patients with anti-depressants , for the patient to find they don't need them if they can get enough B12 .

You can try to get more frequent injections . It will be difficult - I didn't succeed, but perhaps you will . You know we are always here for you . Best wishes .

Gilly27 profile image
Gilly27 in reply to wedgewood

Thank you, was starting to feel like I was going mad given every time I bring up current research with a Dr they completely deny its legitimacy. I'm going to try and pursue the referral (if I can see the Dr who first suggested it - I see a different Dr every time I go to my local practice!). If I keep coming up against a brick wall, I'll think seriously about going down the self injection route. In which case I'll definitely be back asking for advice!

Thanks again.

Gilly27 so many people are apprehensive about self injecting.It is really a few seconds in all and actually nothing to be afraid of as ultimately the person feels better and is in control.Look back at some of my posts as to how to go about it.In difficult situations I always remember my mother bracing me with you are British put your back to the wall and don,t give in.Best of luck.

Gilly27 profile image
Gilly27 in reply to Retren

Thank you for the encouragement! As well as finding the whole self injection thing pretty daunting, I have no idea of how to figure out the right number/frequency of injections.. Any advice on how to determine what's best for me (other than trial and error)?


I would suggest you continue as normal re making appt for your next injection of B12. If there is a problem, ie you're told you're no longer to have them, then make an appt to see your original doctor and ask why your injections have been stopped etc. If s/he says because this other doctor has stopped them, then argue that he has undermined your original doctor's decision to let you have them ... and see where you go from there.

It would be reasonable to argue with the doctor that you are confused with conflicting advice and could it please be noted in your notes that your injections must continue ;) Armed with suitable articles to back up your position, hopefully, all will continue.

I wouldn't see the other doctor again, unless for something totally different and, if he suggests stopping injections, just tell him that you will discuss with the prescribing doctor, thank you very much. ;)

In the meantime, I would get some B12 and start self-injecting as and when appropriate.

Good luck

Gilly27 profile image
Gilly27 in reply to JMN2017

Thanks JMN2017. Do you have any advice on how to determine the appropriate frequency of injections on a DIY basis? Have no idea how to go about figuring out the right routine for me.

wedgewood profile image
wedgewood in reply to Gilly27

Don't worry too much about frequency . YOU CANNOT OVERDOSE ! Some people have to inject daily to keep feeling well because they are not able to store B12. I've injected weekly for over 2 years . You excrete any B12 you can't use , in your urine . B12 is a water soluble vitamin . If you buy in bulk (100 of everything you need ) the cost is about £1.00 per injection . Best wishes .

Hi all - don't know if this will be seen by many or if I should just start a new post but I spoke to a Dr today about when to get my B12, folate and ferritin re-tested. She said, given I am on an iron supplement, my ferritin levels should be tested in 4 months but that B12 isn't usually re-tested until 6 months post-loading injections. Is this accurate in your experience?

She also said it wasn't possible to request the specific blood test that distinguishes active from inactive B12...but knowing how vague and potentially inaccurate the total serum B12 level test is, this seems crazy to me? Do I actually not have the right to request this particular test or is she just trying to fob me off again? Urgh.

Still feeling pretty foggy and listless with my head feeling like it weighs a tonne most days. Dr said I probably won't feel better until at least 6-8 weeks after loading doses/starting iron tablets. Hope she's telling the truth! :/

Sofadetectiv profile image
Sofadetectiv in reply to Gilly27

Not much point testing levels when you're on injections as they will be high/ normal. Some people with these symptoms respond to thiamine- can be low if you eat a lot of white rice and don't have fortified foods like bread/ cereal. No harm in taking a multivitamin daily.

Hi Gilly, I've just started a post almost identical to yours... nothing useful to add I'm afraid, except solidarity!

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