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Pernicious Anaemia Society
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New member - what should I expect from injections

Following a long bout of flu, sinus infection, tooth extraction and post viral fatigue at Christmas I have continued to feel run down. I then noticed several other smaller symptoms like pins and needles, migraines, ridged nails, ringing in left ear all building to a picture of me not being quite myself.

I thought it might be Thyroid but following blood test visited Doctor today who has prescribed 6 injections of B12 in two weeks followed by further blood test and injection every three months.

What can I expect from blood test and how soon will I see results?

5 Replies

Hi Auntieglitterball I'm not a medically trained person but even if I were there is no simple answer to your question "how soon will I see results?" as a lot will depend on the severity and length of time you have been B12 deficient.

Some symptoms may improve rapidly whereas others may even seem to get worse before they get better as the B12 starts repairing the damage caused by the deficiency.

Do you know what your Folate level is? This and B12 help your iron function properly and it is important for the three to be "kept in balance".

Out of interest did you have nitrous oxide when you had dental treatment?

If you have thyroid problems this too will put you at risk of developing a B12 deficiency.

I wish you well and hope you get to feel better soon and if you have any further questions come back as there are many on here who will give you good advice.

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Thank you for the information, yes the Folate is also low. This Doctor seemed quite knowledgeable and said that she would do further tests for Pernicious Anaemia if needed. She was not my normal Doctor but having just moved house to a neighbouring village I used the local practice (3 villages are served by a linked service) and may have struck lucky. It appears from other posts that many other Doctors are not so aware.

BTW I did not have nitrous oxide for dental treatment. I am normally quite a robust person, I just became very run down. I thought a lot of my recent symptoms could have been due to menopause, but it appears that B12 may have been the issue all along.


symptoms of B12 deficiency tend to develop slowly over a period of time as deficiency tends to build up slowly over time.

Your GP may not be as knowledgeable as you think - the protocol if you have neurological symptoms - pins and needles is actually loading shots (3xweekly) until symptoms stop improving - review at 3 weeks - followed by injections every 2 months ... however, they are still more knowledgeable than many.

How long it takes to notice improvement really depends not just on symptoms but also on what is behind each symtpoms - B12 is used by a lot of processes in the body and several processes could be involved in the same process. Some notice improvement quickly - others don't really notice much for months and it also isn't uncommon for aches and pains and immune responses (most of the symptoms you get like temperatures and rashes) when you have an infection to actually get worse initially - like the body goes into overdrive for a while and then quietens down.

Many people find that they run out of B12 long before 3 months - so worth making a list of the symptoms that you do have and keeping a diary of how that varies over time.



You need to post your actual results including their associated ranges. Pay particular attention to Vit D, Folic acid and the B12. Many of the vitamins interact with each other. If you start taking charge of your own situation it will help you enormously. Doctors are very unable to deal with these areas , generally. Your D must be reasonable to enable B12. Your Folic acid must be reasonable to deal with B12 but not precede B12. Your metabolism will also affect their processes. Keep a log and note changes in symptoms.

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I've now had my first shot and managed to get the practice Nurse to print off my blood test results.

Serum B12 was 168ng/L

Serum Folate level was 3.5ug/L

I've realised since collecting my prescription that I have 10 ampules, though have so far only booked six appointments for the loading doses. The surgery seem to think that I will continue to have shots every three months after the initial loading doses.

Should I also take a Folate supplement? This has not been discussed with Doctor. She has asked for me to have another blood test after the loading shots.

Thanks to all for the supportive advice on this site.


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