Pernicious Anaemia Society
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Combined iron and B12 treatment

Hi everyone,

I have finally received a diagnosis of PA after 5 years of recurrent iron deficiency resulting in infusions and low B12 culminating in active B12 deficiency in December 2017. My GPC antibodies were tested and were found to be 149RU/ml (range < 20RU/ml).

Just over two weeks ago I received Ferrinject (Feric Carboxymaltose 1000mg Infusion) and three IMI vitamin B12 1000mcg injections (21/12, 27/12, 30/12). The Ferrinject and first vitamin B12 injection were received on the same day. Both were in Australia.

I am finding my brain is a lot more active and I am dreaming a lot more, but my energy levels are lower than ever. I was wondering has anyone else received the two treatments at the same time and how long did it take to feel improvement in energy? My red blood cells were still in normal size range as the iron and B12 deficiencies were offsetting each other but my MCHC was spot on the lower range and HGB 124.

I have returned to the UK with a letter to give to the GP here, but was wondering, do you have to see a doctor to get a script to receive B12 injections in the UK?

Thanks for your help!


10 Replies

Getting energy levels back can take a while, definitely more than a week or two.

Yes, you do need a prescription for B12 in the UK. Your doctor may insist on doing his own tests and need reminding that testing for B12 after injections have started is pointless.

1 like

Thanks fbirder. My concern is more the dip in energy. I’ve had iron infusions before and been fine. It this is the first time with the B12 and wasn’t expecting to feel like I was going backwards!


I'm not sure why, but many people feel worse before feeling better. I felt quite poorly for a day after each jab. It took a lie before I was feeling more energetic.


Hi Curious123 it would be a good idea to have your Folate level tested too as this and B12 helps your iron to make red blood cells and to function properly in your body.

I wish you well.

1 like

Thanks Clive


It is not uncommon for some symptoms to appear to get worse before they get better as the B12 starts repairing the damage done to your nervous system and your brain starts getting multiple messages from part of the body it had "forgotten about" or lost contact with.

I sometimes liken it to a badly tuned radio on which you have turned the volume up high trying to catch the programme you want when all of a sudden the signal comes in loud and clear and the blast nearly deafens you.

A lot will depend on the severity and longevity of your B12 deficiency as to how long before there is no further improvement or recovery.

Some symptoms will "disappear" quite quickly whereas others may take months or even years. There is no set timescale as we are all different.

I am not a medically trained person but I've had P.A. (a form of B12 deficiency) for more than 45 years.

I wish you well



I'd also suggest reading UK b12 documents below if you haven't already.

BMJ B12 article

BSH Cobalamin and Folate Guidelines

Flowchart from BSH Cobalamin and Folate Guidelines


B12 books I found useful

"What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper

Martyn Hooper is the chair of PAS (Pernicious Anaemia Society). Book is up to date with UK B12 guidelines.

"Living with Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper

Has several case studies.

"Could it Be B12; An Epidemic of Misdiagnoses" by Sally Pacholok and JJ. Stuart (USA authors)

Very comprehensive book about B12 deficiency with lots of case studies.

UK b12 websites

PAS (Pernicious Anaemia Society)


PAS tel no +44 (0)1656 769 717 answerphone

B12 Deficiency Info

I am not medically trained.


I too have experienced this. I have received iron infusions for the last few years due to iron deficiency with celiac. Usually after 2 days I would go from laying on the couch to speed cleaning the house. I now have b12 deficiency as well and have just received my 4th iron infusion since taking the cynocobalamin. It takes me a long time to start feeling better now and the neurological symptoms are definitely at there worst right now. I keep telling myself that it is a sign of healing. I am going to have my mma and homosyctine checked to make sure I have not developed functional deficiency because I am currently on daily injections. I hope you start to feel better soon if you find any answers please post them for me.... all the best in your healing process.


Iron and b12?

Please get tested for h pylori!!!!

H pylori effects your stomach acid!!! It is a known cause for being iron and b12 deficient.


Hi KimberinUS, Thabk you for the recommendation. I have already tested positive to Gastric Parietal Cell Antibodies which can cause both too but I would be good to ensure no H Pylori issue as well to add to things!


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