Pernicious Anaemia Society
14,696 members10,456 posts

B12 questions

Okay a few weeks ago I started b12 injections after real bowel problems - in the last 2 weeks since getting them the stomach has improved

Now one week after they finished it's as bad as ever

Is this linked !? Could I be so deficient that after a week and it's all gone!? Seeing doc tomorrow for review appointment and he's not a believer in retesting x

8 Replies

I don't think a B12 deficiency can cause GI problems. It's normally the other way around - a problem with the gut causes problems with absorption of B12, resulting in a deficiency.

It's likely you changed something else - probably something dietary.


I've definitely not changed anything dietary - deliberately

I also have lupus so there was suggestion it could be causing the lining of stomach to reject the b12


Hi Leeherron79. Ah you have Lupus. As you know, lupus is an autoimmune condition and once you have one autoimmune condition it's quite likely that you will develop other autoimmune conditions. So it is possible that you could perhaps have another autoimmune condition, Pernicious Anaemia.

Do you have any other symptoms? If you go to the Pernicious Anaemia Society Website you can print off a symptom checklist. You might be surprised to find that you have symptoms that you didn't even know were symptoms.

Has anybody suggested that you have an IF antibody test to see if you have PA. Might be a good idea to have this test. And most certainly, your GP (or whoever prescribed the B12 injections) should be trying to find out why you have B12 deficiency.

You say you started B12 injections for 'real bowel problems'. Did you ever have your serum B12 levels checked to see if you are B12 deficient? (Please note, now that you have had B12 injections your serum B12 levels will be high (as they should be), so it will it will no longer be possible to tell if a B12 deficiency was present.

And you say the injections have finished? Bit confused by this since once the initial loading doses have been given, you should be put on a regular regime of B12 injections. Especially if you have neurological symptoms.

People who are B12 deficiency often have low folate, so your medic should also check your folate levels since if these are low, you body will not be able to use the B12 properly (B12 and folate need each other to work properly).

It's quite difficult to try and work out what's going on with so little information so I've just made a couple of comments so that you can come back and ask more questions.

Can I suggest that you read the PAS pinned posts to the right of the page when you log on. These will give you the basics about B12 deficiency and PA, together with the guidelines, diagnostic protocols and treatment regimes etc.

With respect to the doctor's appointment tomorrow, it would be useful to find out: why you were given the B12 injections, get copies of any blood test results previously done (to post here so people can help with interpretation - doctor's often say things are 'normal' when they're not).

Ask what the ongoing regime is for B12 treatment, try to get an IF antibody test (to check for PA), together with folate, FBC, ferritin.

And finally, some people do find the the symptoms of B12 deficiency do return very quickly following their last injection, especially if they have been deficient for some time. But some people manage to last 8 - 12 weeks between injections (but not many). It's very much an individual thing and it's very difficult to be more precise without having more information about exactly what symptoms you experience (be good to see what the symptom check lists turn up 😀).

As I said earlier, it's a bit difficult to,know how to advise you given so little information. What I've tried to do is just get a few things down to see if anything 'fits' what is going on at the moment, especially with your GP appointment coming up tomorrow. It's quite late now so I hope you get this reply in time for it to be of any use.

Please do feel free to post again and ask more questions. Always people here to pop in and help.

Good luck with your GP tomorrow 😀.

1 like

Hi there thanks for this

My b12 was tested and sat at 108 and 118-my doctor said that 110' is normal

They said as it was low/borderline and with my symptoms - tingling sometimes in hands, swollen tongue, jumpy legs, diarrhoea constantly, breathlessness, always tired etc that they'd try it. But doctor wasn't convinced it was b12 -kept saying most likely be lupus

All I know is they said I "wasn't anemic" and my ferritin levels were normal. Not sure if folate been checked..


Hi Leeherron79. Oh dear, it's so easy for doctors to assume that B12 deficiency isn't the cause when you have something else going on!

108 and 118 is very low and most likely to give you symptoms of B12 deficiency. Your results are bumping along at the bottom of the range and this is not good enough for many people. In Japan, treatment for B12 deficiency starts at anything under 500.

There are many cross-over symptoms bewteen Lupus and B12 deficiency but with a B12 that low, you are deficient,

GP's are remarkably I'll-informed about B12 deficiency and most of us here have to become our own experts in order to help our GP's to help us. Sometimes, getting GP's to take B12 deficiency is quite difficult and some GP's become a little hostile if they think their patients 'know too much', so don't be surprised if this happens to,you.

Suggest you continue to push for B12 deficiency treatment. Use the symptoms checklist (as outlined above) and read the PAS pinned posts to the right of this page. They give lots of information about the diagnosis and treatment of B12 deficiency, together with diagnostic protocols. The third pinned post contains a summary of the relevant guidelines, produced by fbirder and listed as Frank Hollis document - it will show you the most relevant guidelines and you can use it to direct your reading.

The Stichting B12 Tekort document (third pinned post) contains information stating that B12 treatment has been proven safe for over 50 years - just in case your GP decides to try and tell you that it is not safe to treat you with B12 - giving very odd reasons why this is so (you' be surprised how many do).

You can put together some information (highlight the most relevant bits) to take along and present to,your GP. Good idea to fill in the symptoms checklist (as discussed above).

As you appear to have neurological symptoms, it is important at you are put on the correct regime for treatment in order to avoid potentially irreversible neurological symptoms. (6 x 1mg Hydroxocobalamin every other day (the loading doses) then 1mg Hydroxocobalamin every other day until no further improvement, then 1mg Hydroxocobalamin every eight weeks. Your GP may not know this.

GP's have a 'prescribing' called the British National Formulary (BNF). Your GP will have one on his desk. The neurological regime is listed in the BNF so you could get your GP to look it up while you're there. It's the second item down, so he / she may have to read further than they usually do.

Finally, the fact that you are just within the reference range is a mute point. All the guidelines state that it is the symptoms that should be treated, not the blood results (see NEQAS document in the pinned posts).

Anyway Leeherron79, hope this helps. Please let us know how you get on and do post again whenever you need further advise or information. Lots of people here to help and support.

Good luck 😀

Oh, and, do ask to have folate and IF antibodies tested (but bear in mind the IF test is only 50% accurate - you can test negative and still have PA). First thing your GP should have done, especially in light of your other autoimmune condition.


I had severe diarrhoea and chronic bowel problem every day for nearly two decades which left me very disabled, confined to bed and exhausted. I was diagnosed with ME and IBS in 1990. In May 2012 Martyn Hooper referred me to Dr Riar who started me on daily methyl injections. Within 2.5 weeks my temperature, blood pressure and heart rate moved from being scarily low to within the normal range. Then wonder of all wonders the most beautiful thing happened my bowel and digestion started to work for the first time. After all those lost years and having given up on ever being well I found myself with normal health and energy, it was the most incredible miracle. Nearly five years later I still need to inject methyl every other day. If I miss a few days then my bowel problem re-emerges, I stop being able to digest properly, the undigested food causes, pain, obstruction, bloating, inflammation and diarrhoea. As soon as I remember my shot it goes away again.


I also found that my gut problems - mainly heart burn - improved when my B12 levels were okay.

Not quite sure what symptoms you are suffering from gut wise but another possibility might be the ileocecal valve - particularly if you are having problems with nausea.

oscillating between diarrhoea (or frequent need to go) and constipation can be a symptom of a B12 deficiency - nobody quite sure why but likely to be the effects of B12 in supporting the nervous system and in particularly the autonomic system that controls those things we do without thinking or with very little thought. urination problems can be similar. This is another area that improved for me with B12 levels getting okay.

Further testing of B12 wouldn't be useful at this point. The serum test looks at what is happening in your blood - but actually B12 needs to be available and processed properly at the cell level and the serum test doesn't tell you what is happening there. Some people do react to high levels of B12 in serum by shutting down mechanisms that transport B12 to cells - like building a dam - and all you can do is flood the system with B12 so it trickles over the top of the dam - so you may be someone who needs to keep their levels very high - which is why everything is starting again symptoms wise.

Suggest you look at list of symptoms - tick everything that applies and monitor what has happened to each of the symptoms - some may be lupus but some may be both ... and with B12 it is the symptoms rather than the test scores that count.


I get a loose stool the day of or the day after my injection. Typically within 24 hours.

I think that the more deficient of B12 I was before the injection, the softer the stool after the injection.

I think that when the body gets B12, a whole lot of metabolism kicks into high gear and floods the blood stream. Mostly with CO2 and water but also other byproducts that the liver filters out and dumps into the gut.

The water should be handled by the kidneys but maybe the osmosis from the gut is less and more water remains in the stool.

Once you know what this symptom is you can treat it like a "good" indication. Although it can be annoying to have the suddenly rush to the toilet. You can anticipate this symptom.

Also you can use its severity to assess how low on B12 you were.

Once you are on sufficient B12, the severity settles down.

If you haven't already, start a logbook of all your symptoms along food and drink and medications. Reset to day zero each time you get your injection. You will see a pattern repeat after each injection.

Once you understand what symptoms your body produces after each injection you can stop worrying about those and start sorting out the remaining ones.

After you gluten and dairy free?


You may also like...