Pernicious Anaemia Society
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Noob qtns, starting IM vs SC

Hey all,

After reading the books of Sally Pacholok and Martyn Hooper I have found my way here!

I may have lots of questions but will try to ask them one or two at a time :)

I don't think I have PA but feel there is a good chance I have a B12 deficiency, I've had two serum B12 tests in the past couple of weeks and they average out at about 270 ng/L

I've only felt very odd for about a month now but looking back I've had a variety of intermittent symptoms over the past few years that could be explained by a steady decline in B12. The most worring of these is, I suspect, neuropathy in the form of tingling limbs, torso and face.

I have what I feel is a very good GP but he's not immune to double blind, placebo controlled, peer reviewed blindness and whilst my progress so far with him has been good, I'm worried it won't be like this going forward.

My first question then is, what are your thoughts on intra muscular vs subcutaneous injections, especially in relation to self administration, is one route significantly better than the other?




9 Replies

I have no medical knowledge, only that gained by having P. A., but have always been led to believe that I. M. Is superior to sub.cut. That is how a doctor administers B12. I self inject into my thigh, but I read on this site that many P.A. sufferers use subcutaneous injections quite successfully .

I believe that a reading of 270 ng/l blood serum is low and you are definitely B12 deficient with those symptoms you mention. Why have you not been tested for P. A. with the Intrinsic Factor antibody test ? It is known to be notoriously unreliable , but if you test positive you do have P,A. If negative , you can still have P.A. and should be treated with B12 injections . Please persevere to get a diagnosis . Must ask if you are a strict vegetarian or vegan or if you are on a medication that can deprive you of B12 e.g. Metformin for diabetes or any P.P.I. or antacid .for gastric problems . I will have expected your doctor to be aware of that though . Having said that it is surprising how ignorant doctors are on the subject of B12 deficiency ! One last possibility ---- FISH TAPEWORM----you can become infested with them if you eat raw or smoked fish . I heard about this when a friend of mine , who worked in an hotel, became B12 deficient . She loved smoked salmon and eat it every day ! The smoking didn't always kill off the fish tapeworm . Her doctor twigged this straightaway and she was treated and recovered quickly . Strangely this episode hasn't put her off smoked salmon, but she freezes it now before eating!

Also have you had any stomach surgery ? This can also affect B12 absorption .

Another risk for B12 absorbtion is Nitrous Oxide gas either as an anaesthetic or recreational use .

Don't know if I've helped you at all, but I think it's always nice if someone responds to a query . Very best wishes to you .


Hey wedgewood!

Many thanks for your reply and kind wishes, due to reasons of time and not boring everyone silly there is a lot of stuff I didn't include in my first post.

I might as well be a little more inclusive with this one as long as concentration allows!! :)

I really noticed something odd following a trip of "excess" to Scotland to a great Inn in the Highlands with six other motorcyclists. We were riding about 250 miles per day and drinking (erm....a canny bit) per night. I'm 45, a bit of a fat boy but usually always active especially cycling and a bit of running.

It was the day after we got back from the trip that I noticed the pins and needles in my limbs and face, I've been a motorcyclist since I was 18 and know the difference between what I was experiencing and vibration white finger type effects.

I was also totally wiped out which again was not usual and felt dizzy and as the week progressed I started to feel very weird. I had a sensation that something was about to happen, something not good. Odd sensations in my torso and pressure in the base of my skull rising upward with a corresponding feeling of unwellness.

I ended up feeling so unwell I had my wife take me to the "urgent care" walk in centre at the local hospital. As usual, by the time I actually saw a doctor (who seemed excellent) I already felt quite a lot better. After examining me she sent me home and instructed me to see my GP.

My GP did FBC, folate, diabetic and B12 tests. All normal said the receptionist.

When I eventually got the numbers I looked up each and every test and the only one out of the ordinary that I could decern was the B12.

I'd already read Sally Pacholoks book a while ago but decided some further reading might be in order and it was at this point I read Martyn's book which added some valuable extra info to things.

Before I received the results of the bloods I had shortlisted a few things I thought might be causing my problems:

Pinched nerve


B12 Deficiency

MS or other AI degenerative disease

Random virus

The bloods seemed to discount diabetes and both docs I saw thought a pinched nerve would affect things less globally.

It was only after looking into B12 deficiency that I remembered lots of symptoms that I attributed to just getting old since most of them were quite mild in nature and seemed to come and go. They seem to have progressed slowly but steadily over the last few years. I'll list them here:

Tingling hands and feet, torso and face

Muscles ache disproportionately, feet feel like they've walked 20 miles by bedtime


Foggy thinking/slow

Altered swallowing (though not painful or difficult)


Feeling of weakness and age

Strange sensations in stomach

Heartbeat in neck



Struggle to exercise

Easy to injure

Slight weight loss without trying

Attacks of pressure in head/flushing

Faint feeling getting up.

Occasional sensations around the kidney band

Mouth ulcers

Exceptionally dry eyes when tired


Can't find the word.

Dark circles under eyes

There are probably a few more I've forgotten.

I returned to see my GP and talk about the things I'd found. I suggested my B12 was low and that I be tested for urinary MMA, Homocysteine, IFAB, GPCAB, vit D and H-Pylori. My doc said he'd talk to "the highly skilled and intelligent biochemists" (his emphasis) at the lab to see what they thought.

A few days later he rang me to say he'd actually spoken to a local Haematologist and that he couldn't do urinary MMA but could do Serum and he couldn't do Homocysteine but would do the rest of the tests.

So far the meat of the results from those tests are that I'm negative for both the Antibody tests and Vit D is normal. I'm still awaiting the results of the H-Pylori and MMA tests.

I did actually test positive for H-Pylori about 15 years ago and was given triple therapy but no retest was applied to see if the treatment was successful.

Until about a year ago I used to do quite a lot of mountain biking and would ski/snowboard each year too, as a result I've had 4 surgeries requiring anaesthetic in the last 6 years. I'm not sure if any of them involved nitrous oxide, I did ask my doctor but he said he'd have to track down each anaesthetist and write to them to find out. I very rarely consume cream but about a month ago I did buy and eat a can of squirty cream which used nitrous oxide as a propellant. I didn't squirt it straight into my mouth or anything but can't help feeling I must have consumed some nitrous.

Another thing which predisposes me to B12 deficiency is that I used to use a lot of ranitidine for acid reflux, something I've completely stopped doing since I realised it could be a problem and I would often take it in advance if I was going to drink alcohol, which I used to do quite a bit socially. I've not drank anything (or taken ibuprofen or paracetamol) though for a month and I still have episodes of reflux.

I'm not vegan or vegetarian nor do I take metformin.

After my last visit to the docs I made the ass-umption that I'd be lucky to get any further B12 related tests and decided somewhat in desperation to try B12 Boost spray (Methyl Cabalamin, Chromium Picolinate and Green tea) and here is where it gets weird.

I've been taking it 2 hourly through the day for approx 3 days but not at night and it really feels like the tingling gets worse after I've taken a dose and in general over the days I've been using it which suggests strongly to me that B12 is the issue but perhaps not in the exact way I suspected.

I should add that the brain fog/poor typing ability I'd been suffering from recently vanished just about instantly.

The tapeworm idea is entirely a possibility and presumably not just fish tapeworm but beef and pork too. According to Martyn's book Eastern Europe can be a source of these and I visited Bulgaria on holiday in March.

I'm going to hopefully see my doctor on Monday and amongst other things will see if I can be tested for tapeworms. I have done a little "examining" but so far can see nothing that might look like tapeworm eggs though apparently like the AB tests tapeworms can be difficult to detect.

Thanks again for the support by way of reply.





There are many causes for a B12deficiency. Some can be 'fixed' like parasites, stomach bacteria (helicobacter), deficiency because of medication, coeliakie (not in all cases) and of course a deficiency due to a lack of B12 in the diet. Most people have a deficiency because of an absorption disorder and then permanent treatment is essential. It does not matter if this is PA or another permanent cause. The treatment is the same. Another cause is just as serious as PA. In most countries B12 is given IM. Because SC is easier learned some people (well in the UK/US a lot) inject SC because of that. In the Netherlands almost everyone who self injects does so IM. Both work, but a lot of people find that they have to inject more frequent with SC.

But ask your GP first to get a firm diagnosis (test MMA if possible before starting treatment, and check for some causes) and get injections from him/her. (better anyway to always get 1st injection(s) with medical supervision because of possible allergy (even though very small chance, still)) Maybe the GP will agree to a trial treatment if MMA is not clear, if not real treatment so at least you start there. You have neuro-symptoms, so injections would be best. Als have some other things checked if you have to go anyway like folate and ferritin.

Have a look at our Pinned Posts (homepage of the forum on the right, or all the way down on the page on mobile) lots of info in there, and guidelines for the GP.


Hey admin,

Thank you for the detailed and informative response. I did try searching for IM vs SC but returned no results (probably because I used acronyms) After I posted the OP the forum then suggested 4 or 5 posts all about IM vs SC !!! :)

My reply to wedgewood contains more information about my recent tests and experiences which I'd value your input on too.

Wifey is a nursing sister and will be all too keen to inflict pain via IM stabbing!!

I'd also like to ask, what is coeliakie?

I did a Google search but all results seemed to be in Dutch and thought perhaps it'd be better to ask here rather than risk a "lost in translation" situation.

Many thanks again.




I'm going to guess that coeliakie is Dutch for 'coeliacs', the autoimmune problem when exposed to gluten.

1 like

Hi fbirder, after posting above, I did in fact use google translate and it would seem you are indeed correct. I think I overthunk it.





Hey fbirder,

Looking at some of your posts it would appear you are somewhat biochemically orientated ;)

I'd be really interested to hear anything you may be inclined to say regarding my story above.

Another aspect of my health which has been a big cause for concern has been oral health and in particular mercury amalgam fillings and root canal filled teeth.

I had some chronic issues (10 years or more duration) which were almost completely resolved after having a large number of mercury amalgams replaced with ceramic fillings in 2008-9.

I understand that methyl mercury is the most damaging form of the metal due to its reactivity in the body, I wondered if you can see any relationship between a body burden of mercury and problems with B12 which I believe also involves a methylation process?





Yes, more a chemist than a biochemist but, as my job involved identifying drug metabolites, I had to learn quite a bit of biochem to understand the metabolic processes.

I'd have to go along with PAS-Admin and suggest that the next steps should be -

1. wait for the MMA result. If that's positive (and your liver is OK) then it's a great sign of a B12 problem. -

2. Look into coeliacs as a possible cause. Peripheral neuropathy, lassitude, brain-fog are all possible symptoms of coeliacs, and you don't need to have the normal GI problems.

My neuropathy is not caused by B12, according to my neurologist. He suspects that it may be coeliacs and, after originally pooh-poohing the idea, I can see where he's coming from. But he's also got a couple of other suggestions, so I've got to go up to London for more tests.

Whilst methyl mercury is an extraordinarily nasty, horrible, compound it's not going to get formed from mercury amalgam. For a start, the amount of mercury one absorbs from fillings is stupendously small.

Then there's the matter of how it would form methyl mercury in the body. Almost all biochemical reactions require an enzyme to carry them out - and there's been no need for an enzyme that catalyses the formation of methyl mercury to evolve - just the opposite.

1 like

Thanks for that fbirder, I'm still waiting for the MMA results and my H-Pylori sample got lost somewhere so I've had to submit another today, it's another waiting game......





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