Pernicious Anaemia Society
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Potassium/chloride/MCH blood results

I was diagnosed with PA a year ago and have been having monthly B12 injections from the GP and also supplementing with sublingual B12 if I exercise or drink alcohol (I don't drink much). It mostly seems to work and I generally feel much better than a year ago.

I do however still get very tired by mid afternoon and asked my GP for blood tests, really thinking about thyroid function as my levels have been fairly close to underactive in the last few years. I'm still waiting for these results.

Some results have come through already though and the following were flagged as abnormal

Serum potassium 3.4 (3.5-5.3)

Serum chloride 90 (95-108)

Mean corpusc haemoglobin (MCH) 32.3 (27.5-32.0)

I'm really surprised by the potassium as I make a big effort to eat potassium rich foods....banana, coconut water, oranges etc.

Chloride I know nothing about.

Has anyone else had a problem with potassium and chloride since having PA? Is it likely to be linked to the PA or is it a separate problem I guess is what I'm wondering.

High MCH is I think the anaemia caused by the B12 deficiency? So do you think it means I should ask for loading doses or more frequent injections?

Any experience or insight would be welcome.


7 Replies

Yes, lots of problems despite mad amounts of potassium rich food and drink!

I didn't know they tested chloride!


That gives you the chance to add potassium chloride into your diet if you wish. It has made all the difference to me and finally got rid of the emotional instability that came on as my B12, etc, levels dropped.

I get it via "Lo-salt" which is available from Co-op stores and is a table salt substitute. (LoSalt is better than the Saxa or cheap alternatives).

Only caveat is be careful if you have high blood pressure. It is better to use than normal salt but still has 33% sodium chloride in it so can raise BP if you have a lot.

Alternatively, I haven't found any tablets that are any good but maybe your GP can prescribe some?


Thanks Denise. I've dashed out and bought the low salt as I've just had my B12 injection this morning so presumably my body will need more potassium than usual. My blood pressure is very low so I should be ok on that score.

I did show the nurse my blood test results and asked if we should check with a dr before doing the injection but she said make an appointment. Which I will after all my results are back.


I forgot to say that you might need extra Magnesium too - that's the latest thing to slow me up and stop my B12 working.

It's easily available as Magnesium sulphate (Epsom Salts). Just be aware that it is a constipation remedy!!!

It is possible to add it to your bath water and I also rub the solution on my body and let it dry. Apparently you can do the same with Magnesium oil but I haven't found that yet.

Someone has just given me some Magnesium Citrate tablets and I'll see how good they are.

I am also going to source a selenium and vitamin E supplement as I am concerned that also might be needed by my body, in excess of what is in the multivitamin and mineral supplement I already take.

Good luck!


You can make "Magnesium Oil " yourself(it's not really an oil) Just buy some magnesium Chloride from Amazon, and add hot water.You can find a recipe on Google. If you buy it ready made it is expensive. Put it in a spray bottle,and away you go. Don't spray it under your arms etc! Using magnesium oil, you don't get the side-effect(i.e. Diarrhoea !) I spray it after my showe,and leave it on all day. But you can rinse it off after say 20 minutes.

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Thank you very much Wedgewood - no wonder I couldn't find it!!

A great idea that has been easy and effective!

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That's a good warning. I think that might explain a few things for me as well. I just eat a few bananas for potassium, partly because high potassium is dangerous as well so taking a supplement seems a bit dodgy unless you know for sure you're too low.

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On the MCH issue, mine has been over the top of range since b12 diagnosis over 5 years ago. Doctor and haematologist don't seem to think it's a problem and will only give me 8 weekly jabs. I have recently begun self injecting so don't yet know whether the MCH will go down. Good luck with getting more and getting better.

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