Pernicious Anaemia Society
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gsts test

hi i have p annemia and have done now for about 8 years, i have heard about a test that you can have done called the gsts test, as i am fine for the first month of my injections but after that i am really tired until my next injection.

apparently you can have this test to see if you need another injection inbetween my normal 3 monthly injections of vitamin b12, i mentioned this to my doctor and she just said no you cannot have a test like that and all she told me was to rest when i was tired, i am 50 now not 90 i dont want to rest in the afternoons like an old lady, as after the new year i am going to hopefully find work and resting is the last thing i need to do hope someone can help thanks joanne1012.

3 Replies

Hi Joanne,

You are not the only one that can not cope with the once every 3 months maintenance hydroxocobalamin B12 jabs. You will find numerous like minded people om the PAS forum, see:


The test you are talking about is the active B12 test and it can help if you feel you are not doing well on current treatment. If your active B12 is low or borderline then another test, MMA can help decide if you are actually B12 def at tissue level. Other issues are worth looking into though such as your folate status as B12 need folate to metabolise (and visa versa) so if you give someone a lot of B12 but they have not got enough folate then the B12 is not fully used, same the otherway round (Its more complicated than that, but to keep it simple). Also serum ferritine (=ironstorage) should be looked at as you need iron/B12/folate and B6 for good blood production.

It is also quite common for people with PA to also have thyroid problems (not neccessarily, but common) so testing thyroid function and antibodies is good if you are not doing as well as is expected etc.

Then naturally there are options to self-treat, but best first get some investigation done if possible. No you should not need to sleep in the afternoon, no you should not feel bad at all, well treated PA should not hinder you to have a "normal " life.

It also is very useful to get copies of all your tests so you can see what is or not tested and what is "normal" and what looks like its going out of range etc.

For info about the active B12 test, see:

The majority (up to 80%) of serum vitamin B12 is not bio-available. Current assays measure total vitamin B12 which leads to a grey area where deficient patients can be missed - there is a poor correlation between circulatory total B12 and B12 status at the tissue level. Conversely patients can inappropriately be classified to a deficient state with the inconvenience and expense of long term supplementation regimes.

The cost of this assay will only be slightly more than a standard serum B12 assay. It will complement GSTS' serum methylmalonic acid assay which is a functional marker of B12 at the tissue level that GSTS is the only service in the UK to offer.

Those wishing to be tested must attend the phlebotomy department at St Thomas' Hospital with a signed letter from their GP requesting the test.

For more information on the Active B12 (holotranscobalamin) test at GSTS please contact the Nutristasis Unit at: or phone Denise Oblein on 020 7188 7188 ext 52471 or you can visit the Axis-Shield website.


It is possible to have a high serum B12 reading but actually be def in active B12, some explanation see:

I hope this all helps you to getting a better quality of life,

Kind regards,



hi marre i did telephone the Natristasis Unit today and have left a message for Denise Oblein to contact me so will wait and see what she says, thanks ever so much for all the information on the GSTS test, i am glad i am not the only one i will reply and let you know what she says if i get an answer joanne1012


Hi Joanne,

Wishing you good luck, and if it takes time for them to reply, e-mail, as that means they can reply when ever they have time etc,

I found them very helpful, the test helped convince my daughter and our GP that she did need B12 injections for life.



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