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Pernicious Anaemia Society
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High b12 with injections

Have posted before, but need to know a couple of things.

My daughter had her b12 tested (again) on the day she had her injection, (before jab). She was unwell and tired as usual with all the usual symptoms, but the test came back 2000. I've read about functional deficiency, and TC11 problems. I need to know what tests she needs to have for the doctor to determine actually why the level reads high and yet she is constantly tired, physically and mentally, why she gets very down and stressed and has the throat problems, getting worse and worse leading up to the injections..which she has at about 7-8 weeks. Apparently her folate is ok. When on the original 12 weeks she still got unwell at about 7 weeks and spent the next five weeks becoming even worse.

If the levels are high and still having symptoms, is choosing to have monthly injections going to be helpful. After all if the levels are already this high with 7 weekly, how would it help. Would it just push the level higher, and then doesn't it affect folate levels. I am quite willing to give b12 in closer stages, but need to know how effective it would be.

Also she is just starting contraceptive pill and so would that cause further problems or confuse the issue.

Nurse said the doctor thinks she should stop b12 for a few months to see what happens. Not in favour.

Than you, in advance.

15 Replies

With you on stopping B12 all together.

I think there is a test for anti-bodies if it is functional B12D but not sure what that would cost and strongly suspect that it wouldn't be available through NHS.

B12 isn't toxic. I use about 4-5 mg a day - equivalent of about 4 shots - otherwise I start to go backwards - suspect that I have functional deficiency and the only way to beat it is to flood the system with so much B12 that the body can't produce enough antibodies so some gets through. I supplement folate (B9) as well - and also some B6 (get headaches otherwise - body can convert B6 to B9 so suspect I get through so much B9 that my body starts to rob my B6 ... but B6 in particular is a vitamin to be wary of overdosing on).

Not sure about the TC11 - is that connected to MTHFR (inability to convert to methyl forms). If it is MTHFR, then its a genetic marker so you'd need GP to ask for a test that looked for that marker. Again, not sure that test costs or if it is available on NHS

Sorry - not really much help on tests.


The TC11 is what transports the b12 to the cells, (think b12 binds to it)...so a test would be to see if there is a deficiency there...as well as seeing if antibodies are around trying to shut down the b12 getting to tissues, as in functional deficiency. Read a lot lately about it. One thing though, in functional deficiency; if antibodies try to shut b12 down when levels are high and so it's not getting to tissues, should we make sure that the levels do not go too high: I mean, would that prevent the body trying to stop the b12 in the first place? But then, what is too high, or low enough so that didn't happen?


Thanks - just thinking about it whilst doing the washing up and realised that TC11 was the transport protein - duhhh!

Under normal circumstances the answer would be to keep B12 levels low enough to ensure that the immune reaction didn't kick in. But - if you have an absorption problem and have had a long term pre-existing deficiency this doesn't seem to work as a strategy and you have to go to the opposite extreme.

This is partly because a B12 shot - the most efficient way of getting B12 in to you - is a very high dose and a high spike that is going to kick off the immune reaction anyway. I know that in the past I felt as if nasal spray had more effect than IM shots ... but then I noticed that my sub-cutaneous shots seemed to take effect much quicker - the spike is a lot lower with sub-cutaneous so probably wasn't getting as much of an anti-body rush.

I did come across a study that reported one individual who had the problem and the only way he could be treated was with continual high levels of B12 - so keeping levels of B12 so high that the anti-bodies can't 'kill' it all.

I suspect that what happens with a at least some of us who find that 12 weeks just doesn't work is that the levels are high enough to beat the immune system for a while but then they move into that area where the immune response starts to win and the symptoms of deficiency all start to come back. The only way to stop that is to get the levles of B12 back up again.

However, this is all conjecture on my part and I'm not in a position to experiment to prove it one way or the other - don't have the biochemistry for one thing ... nor the lab etc. but it fits with my personal experience.


Interested in your reply Gambit. I've been on B12 injections: one a week for 3 weeks (after 4 weeks of one a week, its one a month,) and have not noticed much difference, though I am hoping it is because it perhaps takes time to build up in one before any appreciable difference is known.

I also bought some sub lingual methylcobalamin to supplement (I take one drop 3 to 4 times a day, plus a folate supplement.

I will wait and see if this does make a difference a little bit longer, but if not, I will simply buy the sublingual methylc. and flood my system with B12 that way!!

I am not allowed to buy injection needles in this country (New Zealand,) nor the hydroxocobalamin, only the methylc. subingual.

It against the law here.

Wish I could do my own injections.

But I feel emboldened to take more B12 if after a couple of weeks I am still tired and weak, as you are doing.


Oops! I said I take the sublingual B12 3 times a DAY!

Meant to say 3 times a WEEK!!

If things don't improve after another week or two I will take the sublingual daily (1 drop a day), hopefully, that will be enough.


you should also be able to get hold of nasal sprays, patches, sublingual tablets as well as drops - and you should be able to get hold of different types of B12 in each format as they will be classified as vitamin supplements and not covered by any rules against injectable forms/medication. You may have to hunt around for other forms of B12 but they will be available. Plenty of possibilities to try.

Hope things work out quickly.

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Thank you for your help.

I will google and see whats on offer. If not, I will go to the Health shop.


Do you mean Transcobalamin 11? ncbi.nlm.nih.gov/pubmed/146...

Quote "Partial TC-II deficiency should be suspected in families with megaloblastic anemia and in individuals with neurologic and mental disturbances--despite normal serum vitamin B12 levels. Low serum UBBC and apo TC-II should confirm the diagnosis."


Yes, that's the one. Daughter's been on b12 for four and a half years now, and jab every 7 weeks, and serum level high at that point..doesn't make any difference though. So those two tests, low serum UBBC and apo TX 11 would be the ones to do then? Do you know if being on the supplement will effect the test result, or make no difference to these tests?


I don't know, sorry, I've only just seen this myself, and have never heard of those tests. With the usual B12 tests the supplements do make a difference as you know, but it sounds as if these MIGHT be different as they're tests for someone whose serum levels are normal.


Thanks, I shall ask the doctor about the tests and see what happens :)


Another possibility in addition to those you mentioned might be that your daughter's body is not very good at converting the hydroxo in the shots to the active forms the body can use and she needs the active types.

Even though, as far as I can find out, the only NHS treatment available is hydroxo shots, their page on B12 deficiency recognises that the B12 serum test measures all B12, not just the active: nhs.uk/Conditions/Anaemia-v... I've included this link for your doctor's benefit; I really don't like the sound of stopping the shots without replacing them with another form of B12 supplementation. Her blood may be awash with B12, but if she can't use it, it's not much help.

I don't know what form of folate supplementation she's taking, if any. *If* she has some form of MTHFR mutation, I understand it could mean her body's unable to convert folic acid to folate, but the standard folate test apparently measures folic acid levels in the blood as well as folate. So again, it's possible she's got lots of stuff floating around in her bloodstream that her body can't utilise.

It also may be worth you having a look at Freddd's protocol over on the phoenix rising forum. It's designed for people with chronic fatigue/ME and there are some people for whom it's worked and others who are very uneasy about it, and I don't know enough about the science to make a judgement. But he lists what is needed for each type of cobolamin to work in the body and as far as I can see nobody has disagreed with him on this breakdown; this might be another thing for you to look at if nothing else bears fruit.

In all the above, I'm merely someone going down the same road who's recently been doing a lot of reading on this particular subject to try and find answers as to why the NHS injections aren't working for me and methyl sublinguals have made a difference. I may be mistaken in my interpretation of what I've read, but it may give you a starting point for further exploration.

I'm so sorry to hear of your daughter struggling like this and hope you soon find an answer.


Thank you, the site will be helpful...have to convince a doctor that there is a problem here. It is only because we changed surgeries and the new doctor said she wanted to test levels for herself that the b12 level was tested anyway. . Daft really as daughter has been on injections for over four years. What is the phoenix rising forum, and where is it? I would like to see that site. I have five daughters and three have a b12 problem, so surely the doctor has to see a problem exists. My eldest daughter also has developed fibromyalgia as well, and has had a lot of tests to find out what is causing many 'invisible' health problems..it was a few years before she was diagnosed though and she has some ongoing nerve damage. It was because of her diagnosis that we caught the above daughter's b12 problem earlier when they were testing for glandular fever, (which she didn't have obviously), and we suggested a b12 check. I shall be taking her to the doctor myself as she is just no way going to do battle with anyone...too tired and stressed and inexperienced in dealing with 'the professionals' to do it herself. So, 'forward into battle' go I. :)

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I'm sorry to take so long to reply to you - I've had a couple of days with v little energy and strength. I'm sorry to hear of all of your daughters' battles, though it's fantastic they have you as their advocate!

Okay, the phoenix rising forum home page is here: forums.phoenixrising.me/ind...

The post I was referring to, which identifies which things are needed for each form of B12 to work is the second post on this page, and the section is subtitled 'Dependencies': forums.phoenixrising.me/ind... As I said before, I can't vouch for the accuracy of this information.

I'm sorry in advance if I'm stating the absolutely obvious in what I'm about to say - I suspect you know far more about fibromyalgia than I do - but I found Vitamin D3 and magnesium supplements really helped with what my GP described as fibromyalgia-esque pains. I had my Vit D tested privately before I started supplements and it was within the NHS range, but not optimal according to the Vit D Council and others. I just pass that on on the off-chance it's helpful to your daughter.

I wish you luck in your battles, though I also wish you didn't have to fight them!


Your daughters injection will undoubtedly be Hydroxycobalamain which is an inactive form . If your body is not converting it your serum level will just go up and it will not be getting converted from your serum into tissues , possibly due to the effects of nitrous oxide ( which switches off B12 synthesis - most of us have had this gas at some point medically including during our birth ) or due to an inborn error of metabolism . Methylcobalamin will work much better but surprise surprise a deal was struck to keep methylcobalamin in the private sector where some doctors are charging exorbitant fees per dose . B12 boost spray which goes under the tongue contains methylcobalamin active B12 which is already in a converted form . Methylcobalamin lozengers with co Q 10 to help with absorption in the gut can be effective for lot of us and well worth a try , especially if you cannot bring yourself to source it and self inject ! Good wishes


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