On a standard b12 blood test my levels are normal can I still be b12 deficient?

I have been struggling with small nerve fibre damage for 12 months along with extreme fatigue and other symptoms off the societies web check list. I've seen neurologists, had MRI scans seen numerous doctors and had so many standard tests. The neurologist suggested Effexor for 6 months to try to raise my pain threshold to manage the nerve damage, which I have been doing. However my sister has had similar symptoms to me and she also has normal B12 levels but she responds very well to B12 injections. Within 24 hours her symptoms can start to improve and she manages well with injections and her lifestyle. I have asked my doctor and neurologist to try a B12 injection for me and the response is, why your not anemic? Please can anyone advise I'm so frustrated with trying to get to the bottom of this and rather than treat the symptom try to find the cause?

14 Replies

  • You state your test was normal. Was this active B12 or not. If your active B12 is correct then I would think B12 injection would not be needed. However I am not a doctor etc.

  • You need to have a B12 MMA (methylmalonic acid) test done. This will show you how much B12 is actually "active" in your system versus the total amount of B12 you have.

    I recently got my B12 MMA results back and while the B12 Total Serum number was 628 pmol/L; the MMA test revealed that my B6, B9 (Folic Acid) and B12 was low overall.

    The B12 MMA is fairly new and you will have to ask for it by name. My Doctor didn't even know about. I was told by the lab people that there is only two places in the world processing the MMA test at the moment (Florida and London).

  • Thank you for your time taken to reply. This is very helpful. I am seeing the neurologist tomorrow and will be taking this information with me. Is there a autoimune test I should be asking for too , something to do with an acid? Also I'm taking 2500 sublingual supplements but I thought I had read that it should be a certain type?

  • Hi ,

    I take Jarrows Methyl B12 which contains methylocobalamin which is the ready form of B12....am sure others will explain it better...

    I haven't been formerly diagnosed as having PA but had many of the symptoms of it until I started supporting myself with the B12 sublingual. Since which my symptoms have disappeared and I am doing much better (-finally starting to loose some weight -I suffer with hypothyroidism) -and my nails are growing properly after years and years of being very weak -latterly very very ridged. I suspect i have a had a low b12 issue for many years, suffering with fatigue, forgetfulness and poor ability to sustain activity -all of which has gone now. My GP did do an ordinary b12 blood test -not the active one -and I came up high but that was after 2 months of supplementing. He has put the B12 problem down in my notes though....so if i crash again I will ask for the Active B12 test.

  • Hello waveylines

    I am quite new to this site, so am reading through old questions.

    I was interested to hear how you have benefitted from the B12 vitiamin.

    My B12 was 226, and within the normal level. However as I thought it was borderline, and to cut a long story short, I went back to my Dr. with some info from the B12 site, and she agreed to give me a B12 injection, but refused anymore until we see how things go in 3 months time. This was a couple of weeks ago, and as yet I haven't felt any benefit, perhaps it's early days yet.

    My serum iron came back as 14, and serum folate 10.4 so not sure if I need extra folate?

    You said you had all the symptoms of B12 difficiency, did you have chest palpitations, and pins and needles, with the fatigue, ? I have just recently been having diarrhea and indigestion. I suppose we all have different symptoms but would be interested to know what others have, I also have ridged thumb nails.

    I feel that I should take some suppliments but like you they may alter my B12 and then my Dr. wont want to treat me with anymore injections, but then that means I will have to suffer for 3 months to prove my point to her. It's so awkward.

    I have had several people on this site who have given me so much good advice, and would welcome your opinion.

  • if b12 is under 500 u should fight to get b12 injections

  • Hi please can you tell me what dose of b12 you started on and did you get worsening symptoms to start with. I started on 5000mcg

    But i had such bad effects my symptoms especially neuropathy became much worse. I stopped taking them but the symptoms of b12 defiency are still there. I want to start again but don't know what dose to try also some say that methyl is very strong. What type did you take. I don't know if i sbould try hydroxy. Any suggestions would be welcome.

  • Hi, I was reading your reply about B12 and I have all of the problems you have including hypothyroidism (hashimoto). How long after you started doing sublingual b12 did you start feeling better? I can't seem to tolerate any of the vitamins/minerals in pill form but do a little better with the liquid (I also have low stomach acid)

    Thank you !

  • oh and I forgto to sy that my understanding is that the B vitamin work best together -I therefore take in addition Lamberts high Complex B 50 which also contains a good wallop of folate.

    Hope this helps.

  • Thank you for this information ill change the sub lingual for the methylocoballamin. I hope the neurologist agrees and we try the B12 injections. I too have the autoimune hypothyroidism and now I'm supplementing this with synthroid it's starting to stabilize at 2.4. Seems there's a link sometimes with the B12, iron ferritin and thyroid. It's such a delicate balance ,but its frightening to read how many people have to really convince doctors that they are feeling unwell and its NOT depression! I'm please I've pursued this fight to get to the bottom of things as my sister had her first symptoms 20 years ago. At one point she had to use a wheel chair to get around as she had wobbly legs as she described it. Luckily in those times they tried B12 injections even though her levels were in the normal level. Since then she has had regular shots and has learnt to accept that's just what she has to do without anyone knowing why and without any diagnosis.

  • Hi

    I too have hypothyroidism, IBS like symptons and started 6 months ago with B12 deficiency symptons and felt like I could cheerfully have cut my throat. B12 level in October 2012 was 270. and have now got it upto 368 after 7 weeks of 2,000micrograms of B12 daily. Dr gave me a B12 injection last week but will not allow me more, as currently above normal range, or refer me to a specialist for tests or do tests himself. How did you get referred to Neurologist? Because of B12 levls/your request? I am worried about permanent neurological damage and slow increase in my B12 level (alzheimers in the family, so double worry).


  • Do you have an Endocrinologist for your hypothyroidism? I have Graves disease and to cut a very long story short I managed to convince my Endo to arrange the MMA test for me, even though my Serum B12 was around 300. If this test has an elevated result, it indicates B12 deficiency at tissue level. Mine was elevated. This was done through my private medical insurance, however, might be worth paying for it if you can. I'm having my loading dose of 6 shots at the moment, one more to go. I can tell you that if I'd had just one shot this would have done almost nothing for me. You need the loading dose if you are deficient, your doctor giving you just one injection and then "not allowing you more" is just scandalous. Why did he even bother?

  • I know this was 4 yrs ago but I just had to try. What exactly did you mean about your sister having wobbly legs? I've had a very strange symptom for almost 15 yrs that sounds similar to your sister that doctors just can't seem to figure out. I have the MTHFR mutation, but they tested my b12 and said it was normal. I'm wondering if I should have more tests.

  • get an "active b12" test done this will show how much b12 you are absorbing i was producing plenty of the stuff but none was being absorbed i fought 4 long years before gps would prescribe b12 if gp doesnt help then ask to be reffered to consultant who deals with b12 this is your right

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