Hi. I've posted a couple of times recently so I'll start with a precise and then my ask!
I was diagnosed with Vitamin B12 deficiency in 2015 - I wasn't tested for PA.
I have self-injected for 4 years (hydroxocobalamin) - and got my life back by injecting every other day (sometimes increasing to daily if unwell). In February I was feeling the healthiest I've felt and then in March I felt exhausted and experienced a number of B12 deficiency symptoms (eg tinnitus, parasthesia, shortness of breath). I thought I had an infection/virus and then suspected a bad batch of B12. When I got replacement B12 I injected twice a day for a week or so. I feel quite a bit better - very tired at the end of the day and some tinnitus but ok. However, I am experiencing peripheral neuropathy (or stocking glove neuropathy) and it doesn't seem to be shifting.
I've had all sorts of blood tests and all are normal except a finding that I'm pre-diabetic and bottom end of the scale for Vitamin D.
My GP got in touch with Neurology and got this response: it's just unclear to what the problem is. There are other neuropathy bloods (serum protein electrophoresis/immunoglobins) but it's unclear whether this is definitely neuropathy. It is unlikely that she has functional B12 deficiency with no anaemia/normal MCV (it's very rare). I don't know if there can be a toxic effect from the B12 injections. We can see her but it will take a long time as a routine OP.
My questions!
Have other people experienced a sudden deterioration without being able to identify why? Did you get back from it?
At my appointment my GP suggested that I have injected too much B12. I've gone back to eod but could I have caused the peripheral neuropathy from injecting too much when I increased to twice a day?
Can there be a toxic effect from the B12 injections? (I thought not because it's water soluble but my GP thought it was possible).
What does the neurologist mean by functional B12 deficiency - rather than just B12 deficiency?
Are there any stats about B12 deficiency without anaemia or abnormal MCV? I've got information from NICE and the PA Society that advises that 'neurological symptoms due to cobalamin deficiency may occur in the presence of a normal MCV/Hb' but wonder if it is rare as the neurologist states.
What next? I feel I maybe should be self-injecting more often - but the GP is suggesting having a break to see if it makes a difference. Should I be asking the GP to explore other causes (she's already done tests ruling out some cancers and other diagnoses)? Is it worth getting a private consultation (this would be a stretch for me financially but I feel I do need an expert)?
By the way - the GP has said they may remove my (monthly) prescription because of 'the risk of harm' if they allow it to continue when they know that I self-inject eod. I was asked directly how often I was self-injecting and answered honestly because they were investigating the cause of my symptoms. I have some regret about doing this!
Thanking you in advance. This forum is invaluable.
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LizWilsonpa
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Yes, I have experienced the same and just like you I stepped the injecrions up. This neuro hasn't a clue what he is talking about or has your Gp.
1. You can not overdose on B12 ! What the body does not use is excreted via the urine.
2. B12 is not toxic........ Health Risks from Excessive Vitamin B12
The FNB did not establish a UL for vitamin B12 because of its low potential for toxicity [1]. Even at large doses, vitamin B12 is generally considered to be safe because the body does not store excess amounts.26 Mar 2024
3. You need to take a Vit D supplement to bring you levels up..........
Vitamin D levels are correlated with both vitamin B12 and folate levels. The gastric mucosal effects of vitamin D deficiency may affect other vitamin levels. Vitamin D deficiency may reduce the absorption of B12 and folate via the receptors.
5. Ask your imbacile of a Dr where he got his nutritional training because he hasn't a ruddy clue what he is talking about and is now going to put your health at risk. Ask him to show proof that B12 is toxic.........
Health Risks from Excessive Vitamin B12
The FNB did not establish a UL for vitamin B12 because of its low potential for toxicity [1]. Even at large doses, vitamin B12 is generally considered to be safe because the body does not store excess amounts.26 Mar 2024
7. This Dr is prepared to put your health and wellbeing at risk for the sake of B12 injections...... Try and educate him on his ignorance with the above info. Challenge him by asking him to provide proof that B12 in excess is toxic........ the man is talking out of his ass.
I have got to go I have an appt this morning but hope the above info helps.
Thanks Jillymo - really helpful to know that you have experienced a dip at times also and increased dosage. As soon as I'm challenged I seem to feel helpless - I like your more feisty approach! I've gathered the information that you've sent. Thank you.
Check your ferritin number. It is possible to have ferritin deficiency without anaemia. It is a little known about condition. Your GP probably has no knowledge of it. And the symptoms are similar to B12D. Rule of thumb: with PA a ferritin level of 80-100 is necessary.
Second that Orchard33 Have been told when levels have been in low teens and twenties I've got more than enough! That was what led me to my b12 diagnosis. Feeling rotten & discovered low ferritin first. Mch fine at that stage & b12 high 400's. When I supplemented iron, MCH went overange and b12 lowered considerably, enough to cause very low active b12 & very high mma. So maybe low LizWilsonpa your ferritin is preventing the mcv from being overange at mo,? Yes I feel much better between 80-100. I've been trying to explain to a new Dr that my ferritin often at level 50 shows I still need iron if I pay for iron profile,but they just don't want to know.
I was like you LizWilsonpa and concerned about overdosing 2when I suddenly felt much worse after abt 2 & half yrs, so nauseous & poisoned. I was advised it was low iron agn & then the nausea was blamed on iron tablets.
When I got printout it showed raised mcv & tsh but never got a mention, so in fact was no doubt not enough b12 again, rather than too much! (Id had an upset stomach after eating very well cooked liver & wonder if that was a trigger)
After considerably bad health trying to manage on b12 tablets am determined to keep.optimal in all levels I can & find the right amount of injections that will benefit me now. Mine was diagnosed first time as functional def. due to high mma. But none of this nor the quite scarey neuro symptoms I experiencing this time around have been taking into account and now awaiting to discuss why I've been moved from monthly to 3 monthly! So feel for you and understand your worries but personally I'm more worried about damage from not enough b12 than too much.
Due to Feb your vit d was at its lowest after winter & as mentioned by others caused a prob. It prob doesn't take much to upset the balance with us folk with deficiencies. Take care...
Thanks Jo5454 and Orchard33 - my ferritin is about 60 which is much better than previously. I note your responses and those of others that being off kilter with my vitamins may be having more effect than I would expect it to. I will be more consistent with my vitamin supplements to see if that supports recovery. Many thanks.
Thanks all - these comments really resonate. I keep reflecting that I can't believe how much I was doing - and that's probably the point, too much! At the same time I'm conscious it might not be anything to do with B12. I have a new supply of Pascoe B12 depot which has previously worked really well for me so hoping it brings some improvement.
Functional B12 deficiency : where there is a malfunction in transporting B12 to where it is needed (cells/ tissues). A complex journey requiring links along the way, one that starts with salivary haptocorrin (r- binder) forming a protective coating for the B12 in food (extrinsic factor). I have not seen this discussed much, either here or in research, but since I have a saliva duct problem, I once brought this possibility up with a senior ENT consultant, who was certain this would cause issues with B12 deficiency.
More often, functional B12 deficiency can be a failure of MMA and B12 to form a link in the bloodstream - so this could show as a build-up of both in serum tests (high B12 level, high MMA level) yet the patient would obviously still experience B12 deficiency symptoms. In "ordinary" B12 deficiency, the injections (introduced B12) would raise the amount of B12 in the bloodstream and any build-up of MMA there would form a link with this and the transport to cells and tissues would begin to replace the lack. This should reduce the MMA down to normal levels very quickly, certainly by the time the loading dose was complete.
I was diagnosed with functional B12 deficiency by my GP - I'd been found to have B12 deficiency, had been started on the usual NHS regime of B12 injections : 6 injections (loading dose) followed by a maintenance dose of 1 injection every 3 months. I continued to deteriorate noticeably, and after treating both low ferritin and folate, my GP also had my MMA tested. This was raised, and because she had also already ruled out renal problems, the testing laboratory confirmed her diagnosis. Later SIBO was also ruled out as a cause. My injections were increased immediately to 2 a week. Finally, I stopped getting worse, and then, very gradually, started improving.
After three months on this frequency, I no longer needed to ask the administering nurse if she had finished, as I could feel that the injection had been done. My GP could see visible improvements (everyone noticed the difference) and was happy to continue with this effective frequency. The nurses ? Not so delighted, and some expressed concerns - but then this was new to them.
After another 3 months, I started deteriorating again. The GP decided that this had gone beyond the remit of primary care and passed me on to secondary : firstly, I think, haematologists. She also dropped my injection frequency down to 1 injection a month - which she had told me previously would be my maintenance level. This disappointed me - I was nowhere close to a state of health that I'd have wanted to maintain yet !
The haematologists were even more of a disappointment. I was warned on my first visit that B12 was toxic, carcinogenic and highly addictive ! I hadn't geared up for that at all, but had written out a two-page symptoms list. Sufficiently interesting that they wanted a copy for their files (not mine ?) - but I already knew this was not going to go anywhere. After asking many questions, one decided that the sole cause of my dizziness, cognitive and memory issues, exhaustion and bouts of uncontrollable loud overlapping yawns (air-hunger) was being an ex-smoker ! My brain not getting enough oxygen ! (Even my GP raised an exasperated eyebrow at that one ). My questions, the consultant promised, would be answered on my next visit. So at least I was getting another appointment.
Over the next appointments there, I had plenty of blood tests. 4 MMA tests all showed raised results. The haematologists decided that perhaps the MMA result was "my normal" and that the GP should not give me more than 1 B12 injection every 2 months.
I started self injecting EOD - and told my doctor the day after my first one. I needed to get back to work on a phased return - or lose my job.
I was sent to a neurologist: nerve function tests (electricity) and brain scan. These (surprisingly) showed nothing unusual.
I was sent to many consultants after that. Gastroenterologists for bowel issues: 2 polyps removed, patchy gastric metaplasia and flattened mucosa in duodenum. All I know is Coeliac disease was ruled out. They decided I had IBS. My GP disagreed. I had a SIBO breath test where the result was inconclusive. She trialled me with antibiotics for SIBO. I had a bad reaction (some can deplete B12) - constant vertigo and headache - so it was decided to rule that out as a possible cause for raised MMA.
Finally I was sent to Adult Inherited Metabolic Diseases for a DNA test. By then, my MMA had dropped into range for the first time. This was the 6th MMA test and three years had passed since the 1st one, requested by my GP. Sadly, Metabolics consultants could find no genetic cause. They were, I think, as disappointed as I was.
Nothing else was ever discovered, so I can only assume that my GP was right in her diagnosis, that I have functional B12 deficiency, cause undetected. I am also assuming that my frequent injections (EOD) finally managed to bring down my MMA three years later.
I now self inject twice a week and find this frequency can keep most of my symptoms at a manageable level most of the time. No miracle cure. This frequency, by the way, is the one I was put on when the GP first had my MMA tested, the one that made a difference. It is also the one that Metabolics consultants advise, should a genetic cause be found in DNA tests. Regrettably, some GPs take no notice of this advice - and the poor patient has to return, in a far worse state, to the Metabolics team to be rescued.
An Oral Medicine department has been trying to help me with angular cheilitis, burning tongue and saliva duct strictures. The daily burning tongue is now considered to be due to nerve damage. The other two are cyclical symptoms and mainly controlled now.
I was honest about my self injection regime and yes, this honesty can cause problems, mainly by completely distracting the GP/consultant from the actual problem being presented. Some have regretted this decision, but sometimes, attitudes have changed given time.
My NHS B12 injections were stopped by another doctor, a new one that I'd never met before, while my usual GP was on holiday. I'd seen the panic on his face and realised a letter would be in the post the minute I walked out the surgery door !
This action actually changed nothing for me. My usual GP returned, continued to monitor my ferritin, folate, thyroid and vitamin D regularly - and never included B12 on the list. A shame she has now left the practice.
There is not much in the way of useful research about functional B12 deficiency, but Martin Turner and Kevin Talbot (neurologists from John Radcliffe Hospital, Oxford) wrote an article for Practical Neurology in 2009, Neurological : " Functional vitamin B12 deficiency".
Hi Cherylclaire , this is very interesting.However I can't get the link to work. And all I can find via search is a summary and paid-only access to the article via the BMJ. I've gone to the Practical Neurology site and searched too but it doesn't come up! Have you got another link to it? Thanks!
Thanks Cherylclaire - it's so helpful hearing about other people's journeys and outcomes. I'll look at the article you've provided - although I found your description was the step I needed towards understanding. When you mention Metabolics consultants do you mean the nutritional advice from Metabolics? Really appreciate you providing a detailed reply.
Adult Inherited Metabolic Diseases consultants - they look at genetic causes for conditions. They are usually the consultants at the end of a long search, and I think they recognise that. Perhaps for this reason, I found them apologetic for being unable to find answers for me, supportive and kind.
Agree with everyone saying to recheck some of your other levels - folate and ferritin come to mind especially. I’ve been feeling worse recently and we found out my folate had dropped again. The functions we use B12 for also often use folate and iron so if you were injecting quite a lot you might have been healing and then using them up quicker!
Thanks - a helpful prompt. I was thinking my levels were good (better than they've sometimes been) but I think I may need to review this because they're low on the scale.
Hi Sleepybunny - I have kept copies of your replies to previous queries and they're my go-to when I'm wanting a reminder of all things B12 deficiency/PA! Thanks for taking the time to reply specifically to my queries - it's so helpful. I was feeling overwhelmed about finding appropriate responses and links to share with the GP. Very much appreciated.
I've seen recommendations that folate and iron should be checked after b12 treatment has started. B12 may cause the body to use more of these nutrients, so levels may drop after treatment is started. It's also recommended to eat enough potassium, but it's better to get this mineral from food than supplements. In general, make sure to get good nutrition, because a single vitamin isn't doing its work on its own, everything is more or less connected.
Yes, I’ve had a second loading dose from Dr and this time around seems they check ferritin, full blood count, b12/folate at 8 wks after 6th injection…so at least that much has filtered through into the system.
Thanks. Your reply and others have given me a really good reminder that I need to make sure I keep considering my nutritional needs. I have a pretty good diet but do think I need to ensure I keep on supplementing also having read responses. I'll look up about potassium in food. Much appreciated.
AN UPDATE - my GP rang and she'd read my email and the information I'd sent through. Tbh, despite the outcome, I do really rate her and she seems very considered.
However, she has told me that they're withdrawing my B12 prescription. She said that the prescribers feel that they can't be seen to be supporting me taking more than the 'recommended' dosage. If I tell them that I'm only self-injecting once a month (as per my prescription) then I am able to have the prescription reinstated - or I can start getting my prescription again if I can't get B12 from an alternative source. I told her that I won't lie about my treatment.
She also told me that they have a number of patients wanting B12 more frequently and are therefore reviewing the surgery's current guidance. The proposal is that they will not allow any new patients to have B12 more frequently that every 10 weeks.
I am a bit lost for words - and out of fighting spirit! To be told that they're not going to judge the frequency of B12 injections on symptoms as per NICE but on an arbitrary cut-off point is shocking.
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Have been told when levels have been in low teens and twenties I've got more than enough! That was what led me to my b12 diagnosis. Feeling rotten & discovered low ferritin first. Mch fine at that stage & b12 high 400's. When I supplemented iron, MCH went overange and b12 lowered considerably, enough to cause very low active b12 & very high mma. So maybe low LizWilsonpa your ferritin is preventing the mcv from being overange at mo,? Yes I feel much better between 80-100. I've been trying to explain to a new Dr that my ferritin often at level 50 shows I still need iron if I pay for iron profile,but they just don't want to know.
Nerve Conduction Test 
Peripheral Neuropathy !!
Progress of Peripheral Neuropathy 
Gluten and B12 deficiency 
