Pernicious Anaemia Society

b12 another blood test even though I get 12 weekly injection of b12

I have been diagnosed with P,A and have been receiving b12 injection 12 weekly but feel I need them 8 weekly but my GP wont agree, Now a new know it all young doctor has made me have a blood test? The results were Serum vitamin B12 level( XE2pf) 1500 ng/l(180.0-900.0) Serum folate level 22.0 ug/L (4.0-20.0) above high reference limit, What does this mean? I need to find out before my next injecton in 2 weeks

5 Replies

It means that your doctor wasted a pile of NHS money on a test that will tell them nothing.

Expert opinion (the British Committee on Standards in Haematology) say that symptoms, not numbers, should be treated.

More info in the pinned posts.


Your serum b12 level is above reference range as is your folate level.

However, serum B12 is a poor guide to whether you are B12 deficient when you haven't been supplementing - totally meaningless after you have had loading shots and are on maintenance doses unless it comes back low. The reference range just can't be applied as any sort of guide after you have had loading shots and are on maintenance doses - the average level at which people feel ok after loading doses is actually off the top of the normal range. for me the level at which I feel okay now is actually nearer the upper range of measurable.


Very few GPs understand the complexities of PA/ B12 deficiency.

You could try writing to them, quoting this latest BMJ research document :

It clearly states (bottom of page 4 under 'How is Response to treatment assessed' ) that, once b12 treatment is started, the test results don't mean anything and blood levels are not reflective of how effective the treatment is - it is the clinical condition of the patient that matters:

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

This might also help :

"Conclusion: A vitamin B12 deficiency can cause many different symptoms, among which are serious neurological problems. The treatment with high dose B12 injections is not only completely safe but fortunately also very effective. With the right treatment patients can recover completely. Starting straight away with treatment is essential, as is the continuing treatment in order to give the body enough B12 to fully recover

"After a year: The need for quick and correct treatment is emphasised further by the fact that after a year of treatment only 4 % of patients are fully recovered. Fortunately half of the patients have experienced a lot of improvement in their symptoms after a year of treatment but there are still a lot of patients with remaining symptoms, who could possibly have recovered if their treatment was started promptly and adequately."

1 like

hi viking 78 "What does this mean?" probably a fight on your hands, like I had, telling you you are now normal and don't need any more injections. I hope not but . . .

Let us know now you get on.++


My doctor retested my B12, came back 1872 pg/ml (190-683). Now my injections have been stopped. To quote, 'no court in the land would allow injections when B12 is that high'! AND, It can't be working anyway, as I still have symptoms! ARGH!!!!

My advice would be to go well prepared and bring someone with you!


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