More B12 injections. What's next? - Pernicious Anaemi...

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More B12 injections. What's next?


I have, for the past few years, been suffering from symptoms relating to B12 deficiency - extreme tiredness and depression being the main two. I ignored it for a long time, eventually making an appointment with my GP sometime in 2014. She took a blood test, put me on cyanocobalamin and folic acid and, from my other symptoms, diagnosed me with anxiety/depression.

I had been on the tablets for over a year before going back and asking for another blood test in December 2015. It came back saying my B12 and folate levels were low so I had the "loading dose" of injections just before Christmas. My last injection was on Christmas Eve and I had a blood test taken 10 days later.

Results said my B12 level was at 93 and my folate was around 2.4. My GP said I should have another "loading dose" when I went to see her on the 28th of January. I'm about to start week 2 of my injections and, after that, I have to get 1 a week for 4 weeks and then get a blood test after two months.

What will happen if the results come back and my levels are still too low?

5 Replies

kcxo, I am not saying I know what your problem is as I am in a quandary as well. I have just done a 23 and me test and found I have a few mutations but the mthfr gene the methylalation part of it all is quite confusing, I have discovered that there are

cyanocobalamin/ hydroxycobalamin/ methylcobalamin/adenosycobalamin/ the last one is the active b12 from what I have read, while trying to read up on some of my mutations, I discovered this, and some do well on any one of those listed and some don't, so I was wondering if perhaps you may need anyone of the others from what

she is giving you, and all our genes are different, we are not clones, --- as I am struggling myself with this, don't take my word for granted, look up some of these and try to get some concrete evidence and tak e that with you, it may be a case of just changing the b12 type med, who knows.

my point is, if what she is giving you isn't working for you- then why?


It sounds like you have problems absorbing B12 from your food - and that may also be affecting your ability to absorb folate. Most B12 (99%) is absorbed in the ileum and that is where things tend to go wrong. It sounds like your doctor assumed that the problem was lack of B12/folate in your diet but the fact that the tablets haven't worked implies that this was an incorrect assumption on their part ... and possibly a negligent assumption. Unless you are strict vegan with very little meat or dairy in your diet it is much more likely that an deficiency is caused by an absorption problem.

One common cause of absorption problems is levels of acidity dropping in your gut as you get older. Others are an autoimmune response that attacks the absorption mechanisms in the ileum. Then there are surgical or genetic problems affecting the ileum ... and there are also various drug interactions that can stop you absorbing B12

If you have an absorption problem with B12 then you are no longer able to absorb or store B12. Tablets are not likely to be of much use unless they are really high dose - between 1000-10000mcg, and even then they may not be a good way of getting B12 in to you. So you have basically been allowed to become more and more deficient. Your doctor should really have put you on injections to start off with.

The loading shots are a different way of getting B12 in to you that bypasses the gut - and hence the ileum so it is much more efficient way of getting B12 into your body. This should mean that you have enough B12 and, providing that you also have enough folate then you should be able to process that and start healing all the damage that has been done whilst you were deficient. However, if you aren't getting sufficient folate then your blood serum levels will rise but you won't be able to use the B12. You are likely to need a lot of folate whilst your body is working to correct everything that has gone wrong.

Even if your blood tests are high after the loading shots you will still need regular maintenance shots - regimes vary from country to country but usually if you they are using cyanocobalamin then you should have shots every month.

Hope that the shots (and managing to get enough folate in to you does the trick. There are some other things that can make life complicated - like MTHFR which is a problem converting B12 and folate (B9) to the methylated forms that are used at the cell level but it doesn't sound as if that is part of your problem at the moment.


I have assumed you're based in the UK.

You mention tingling and pins and needles in another thread . These are usually considered to be neuro symptoms. Treatment for those with B12 deficiency with neuro symptoms includes extended loading doses until symptoms have stopped improving.


Symptoms checklist in PAS library. I ticked all my symptoms and gave a copy to GP.

Info for GP on treatment can be found in

BNF (British national formulary) Chapter 9 Section 1.2

BCSH Cobalamin and Folate guidelines

The Management section in above link has similar info to the BNF.

I would recommend reading the whole "BCSH Cobalamin and Folate Guidelines" as they are fairly recent (2014). Some GPs may not have read these guidelines. I made sure my GP had a copy with relevant passages highlighted.

"She took a blood test, put me on cyanocobalamin "

I'm surprised you were put on Cyanocobalamin tablets first. My understanding is that patients with B12 deficiency and neurological symptoms should receive injections and also be referred to a haematologist. Sadly some haematologists are not that well informed about B12 deficiency.

What does the GP think is causing your B12 deficiency? What they think is the cause can affect the treatment they give you. link below has info on causes.

Have you had an IFA(Intrinsic factor Antibody) test? This can help to diagnose PA (Pernicious Anaemia) but is not always reliable. People can still have PA even if IFA test negative. The BCSH Cobalamin Guidelines mention Antibody Negative PA.

Link below about testing for B12 deficiency.

I found it very helpful to talk to the PAS (Pernicious anaemia society), If you leave a message they should get back to you within a few days.


01656 769 717

KCxo in reply to Sleepybunny

Thanks for your reply.

My GP did request that they check my intrinsic factor but they forgot to test it the first time around so I got the test done again and, just my luck, my GP left the practice before I could get my results. When I was referred to someone else about my blood tests, she didn't mention that anything was wrong apart from low B12 and folate, so I'm assuming it was fine.

"so I'm assuming it was fine"

I learnt through experience never to assume everything is okay after finding out on more than one occasion that results I was told were normal face to face or over the phone were not always normal when I got the copies. I get copies of every blood result.

Even if an IFA test is negative, it is still possible to have PA. the BCSH Cobalamin guidelines mention Antibody Negative PA. I found page 29 of the BCSh Cobalamin guidelines useful. this mentions antibody negative PA.

There was someone on this forum who found out they had had tests some time ago that indicated they had PA (Pernicious Anaemia) but they weren't told at the time....

You have a right to have copies/access to results. Most surgeries will charge to make a copy.

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