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Pernicious Anaemia Society
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Tests for B12d?

Are there any reliable tests available to prove (or otherwise) that someone is B12 deficient? In 2008 in Spain I was diagnosed, after six months of illness and unexplained symptoms, by a test for homocysteine levels. I was given weekly loading doses for 1 month thereafter 3 monthly and became fit again. Some years later after traumatic events and relocation to the UK my injections were missed and after some months of returning symptoms I finally, with PA society's help and advice, got the UK doctor to resume my injections but only 3 monthly with no initial loading doses. I have found that my symptoms are returning after only a month and have been supplementing with tablets and oral spray. The doctor refused to give me injections more frequently but recently said would review after a blood test. That came back at over 700 so have now been told I can have one more injection only (13 weeks since the last) thereafter tablets only as the level is so high. Where do I go from here? Is there no way of proving that B12 is needed? I am frankly scared as my neurological symptoms are becoming marked.

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You need to have an active B12 test .,or an MMA test . The usual test for B12 only reveals the total amount in the blood serum , not the amount available for you to use . Up to 80 % is inactive B12. Also testing once supplementation has started is useless. It is bound to show high , It will be difficult to get those other tests . Some doctors do not know about them

Have you been tested for Pernicious Anaemia? This is the test for antibodies to the Intrinsic Factor . If positive You have PA , if negative you might have it!

I forgot to ask if you were vegan or strict vegetarian . These diets can lead to B 12 deficiency . But this can be easily remidied by taking tablets , so I assume you are not .

Most doctors are really ignorant about B12 deficiency/Pernicious Anaemia . It is always a struggle to get the correct treatment . I have P. A with a permanent neurological problem because of delayed disgnosis and treatment ( I had to go to a private GP to get diagnosis ) I am only allowed 1 injection every 3 months but symptoms return long before that. So now I have to self inject to keep well .I get B12 ampoules (Hydroxocobalamin) from Germany( only obtainable here on prescription)

I wish you all the best in getting the correct treatment , but it will be difficult . I was told that by my ignorant GP that having more than 1 injection every 3 months was toxic . This is not true . Excess is excreted as B 12 is a water-soluble vitamin . There are scientific papers to this effect

If you find you have to resort to self- injections , come back here for advice . All the very best .


Hi Wedgwood . May I ask where you obtained your private diagnosis from ? I'm not sure if we're allowed to post Dr's names in public forum so maybe you could message me privately ?

I've given my GPs so much info and had 3 appointments with them so far . The last being last night with a senior GP . They will let me know in a few days but I am considering going private but raising the funds for this would be difficult at the moment as I've been unable to work as have many health issues .

I have most of the neurological symptoms so I need to move fast to stop further nerve damage in the interim period until I can see a neurologist etc.

Many thanks xx


The Drs are impossible, aren't they? I know what you mean and when I got to the point that anything was better than how I felt I decided to self inject - I had nothing to lose. I found it is nowhere near as bad as the thought of it and after a year of daily jabs and cofactors I'm much better and many of my neurological symptoms are resolved.

For more information on sourcing supplies for this you could look up my profile by double clicking on my name and see my post "My Experiences".

Keep in touch! Good luck!


I think the Active B12 test may be affected if you have supplemented recently. See 4th question in this link.



Have you read the following document?

"BCSH Cobalamin and Folate Guidelines" which came out in 2014. I found page 29 useful as its a diagnosis flowchart which shows the process GPs should follow with someone they suspect of having B12 deficiency.

Page 8 in the BCSH Cobalamin Guideliens says that no further testing of cobalamin (B12)is required after supplementation starts, this page also covers the recommended treatment of b12 deficiency.

I gave a copy to my GPs along with a copy of Martyn Hooper's latest book which is up to date with current UK guidelines.

"What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency"

fbirder has compiled a summary of useful quotes from mainly UK B12 documents which may help in discussions with medics. If you search his posts you should find a link or you could pm him.

Your local CCG if you are in England may be able to tell you if the BCSH Cobalamin Guidelines are being followed in your area. MPs may also be able to help find out info or perhaps a FOI (Freedom of Information) request to local NHS website.


Unhappy with treatment?






"The doctor refused to give me injections more frequently"

Do you have neurological symptoms? My understanding ( see page 8 BCSH Cobalamin Guidelines) is that people with B12 deficiency with neuro symptoms should have maintenance injections every 2 months. This info is in BNF(British national formulary Chapter 9 Section 1.2


See PAS Symptoms Checklist in above link.


Wow sleepybunny, thank you! So much reading matter it will keep me occupied for hours. One thought - I have joined a health club to try and get fit (not overweight just enjoy exercise) but after second swimming session this week felt terrible!! Neuro feelings appalling, tingling, muscle and joint aches, etc. As my last injection is due tomorrow - any ideas anyone?

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As you have had contact with the PAS in the past, perhaps you can get them to intervene again. Are you a PAS member?


PAS tel no 01656 769 717

PAS office open Mon-Sat 8am-2pm

Posts from Martyn Hooper's blog showing how the PAS has helped people who have had their injections stopped.



"Neuro feelings appalling, tingling, muscle and joint aches"

See this other symptoms list.


Have you ever had an IFA test?

You might find it interesting to look at MTHFR gene mutations which can influence homocysteine levels in some cases. MTHFR gene mutation tests are available privately.

With neuro symptoms my understanding is that the treatament should follow info in Management section in next link. Same info is on page 8 BCSH Cobalamin Guidelines.



Hi Beattie-75,

I understand about exercise wiping out B12. I even posted about it because I had to increase my injections after I started an aqua fit class. Good luck with getting the B12 you need! :-)

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700 is over their cut off point, but you have had injections and taken other supplements so its not surprising. You need to try to get your gp to treat symptoms or find out why you have them in the first place.

Fbirder, a regular on here will tell you his readings dont even come within the upper limits, the lab cant even read them, but he has no problems either with his gp or the quantity, i believe its over 6000.


so infuriating at the lack of knowledge and arrogance,and the damage done with nerves - I was told that my levels were enough at 587- I am always tired always asleep no energy hairloss nerve problems, I did a gene test and have a mthfr methyl prob and I wrote to the haemo dept and told them! I have 1 every 3 months ,only had one injection so far, in june, and I am still sleeping all day, no energy, nerve probs hairloss, if only they were in our shoes- mma? not sure how they do active b12 or who does them


Check out Sublingual Methylcobalamin!


thanks joycekay I did have some and must get more I already hav e to buy active b12 in supplemnts and b- minus folate free, I buy a ton of stuff fo r lyme and I am so short of cash at thi s rate having to buy everything and naturethroid too.

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Thanks Lisahelen, it is great to feel there are people out there who understand! I cannot even discuss this my own sister who always says 'here she goes again' and the last time I was battling with the medical profession the GP had a heart attack the following day!!!


You can "speak" to us. We will always offer not only advice but sympathy and congratulations



Are you taking Methylcobalamin or Cyanocobalamin? Sublingual Methylcobalamin bypasses the stomach ,goes directly to the brain and nervous system. Cyanocobalamin does not. Lab serum blood test only show what is in your blood , not what the body is absorbing.


Are you taking Methylcobalamin or Cyanocobalamin? Sublingual Methylcobalamin bypasses the stomach ,goes directly to the brain and nervous system. Cyanocobalamin does not. Lab serum blood test only show what is in your blood , not what the body is absorbing.

Injections (which is what Beattie-75 is taking) do a much better job of going directly to the cells in the body. An injection will get all of the dose into the body. With a sublingual lozenge part of the dose (an unknown, varying part) will be swallowed into the stomach. So an injection is a much more reliable way of getting a known amount into the body.

Lab serum blood tests do show what is in the blood - which is the best way to determine what the body is absorbing.

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It is a pity that GPs tend to be so ignorant when treating B12 deficiency - like they haven't moved on from the days of using leaches to let blood ... there is a bit of me that hesitates to use that analogy as there is at least one condition for which leaches would be the appropriate treatment but ....

Blood results after you have had and are on shots really don't mean anything unless they continue to be low. It isn't the amount of B12 in your blood that is important it is what is going on at the cell level. This is where the MMA and homocysteine tests can help as they look at harmful waste products that build up if there isn't enough B12 available to your cells. They aren't used as first line tests because they can be affected by other things.

There really doesn't seem to be any scientific backing for 3 months as the frequency for maintenance shots - the nearest anyone has managed to come up with is a study in the 60s (when it started to move away from monthly in the UK) which showed that on average people retain hydroxo twice as long as cyano ... but the study was also quite clear that there is so much variation between individuals that there were also significant numbers of people who retain cyano longer than hydroxo ... so really not a basis for moving to two monthly if you don't want to harm your patients. The move to 3 months seems to have been down to penny pinching of the worst sort.

If you have an absorption problem then that means you can't store and recycle B12 normally - stored in liver and then released in bile into the ileum where it's reabsorbed into the blood ... unless you have an absorption problem in which case it just passes through your gut - so you will become deficient again over time.

And also back to the fact that it isn't the level of B12 in your blood that counts - it is what is going on at the cell level and it is perfectly possible to have lots in your blood but very little of it available at the cell level - known as functional B12 deficiency. Methylation problems are one possible reason - auto-immune responses that try to keep the B12 in the blood when levels start to get high is another possibility.

Your body uses B12 in the process that releases energy in your muscles so not surprised that you have been able to tie recurrence of neuro symptoms to periods of exercise - sports coaches and trainers tend to be more aware of B12 than the average GP!

The materials that Sleepybunny has pointed you to may help to educate your GP but at the end of the day you may need to look to treating yourself and suggested by Lisahelen. The options before you get to self injection included sub-lingual lozenges and sprays (idea is that they are absorbed through membranes in the mouth rather than in the gut), nasal sprays and sublingual patches. This gives you the opportunity to look at other forms of B12 and how you respond to them. They aren't covered by prescription only legislation relating to injectible substances.

You may want to think about supplementing B9 either as folic acid or a methylated form just to make sure that processing extra B12 doesn't leave you deficient and stop you being able to use any more B12.


Hi Beattie-75 ...

Have you had your thyroid correctly tested ? Low thyroid and low B12 do go hand in hand.

If you have neurological symptoms you should have regular B12 injections until symptoms improve. Check out fbirder on this forum....


Thank you all so much, all very helpful and a lot to take in. Am off for last injection tomorrow!!!!!!

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