Blood tests advice please: Hi I... - Pernicious Anaemi...

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Blood tests advice please

joleen19832 profile image


I recently had blood tests repeated after dr has withdrew my injections (last one was in September) and went back complaining symptoms returning although she put me in daily oral B12. My levels for B12 have come back really high so I’m confused as to why I feel like I have been going down hill. She has said bloods are all fine and thinks I have CFS, I told her I was in total disagreement and want it investigating further or second opinion as too many positives have come from injections but the symptoms seem to return after 8-9 weeks. I was wondering if anyone could advise on the result below, she has referred me to rheumatology and Told me she doesn’t need to see me again and I go 2nd jan so looking to get advice so I can hopefully get some sort of answers as to why I feel so rubbish.

My old results taken in January B12 was 104. There also seems to be more on this full blood count than in jan as I had no mch reading just mcv which was 98.1 and mchc at 341

Any advice would be appreciated

5 Replies
Gambit62 profile image

Your GP is not treating you in accordance with UK guidelines, which would not include retesting levels.

Unfortunately injections mean that the serum B12 test isn't one that can be used to manage B12 treatment.

After an injection your levels will be really high and then they will fall over time. The rate at which this happens varies significantly from individual to individual. Additionally a significant number of people respond to raised serum B12 levels in a way that makes the process that allows B12 to pass from your blood into your cells much less efficient leading to a functional B12 deficiency - all the symptoms of B12 deficiency but high serum B12. This reaction also seems to keep the B12 in your blood for longer, which means that high serum B12 levels after loading shots are impossible to interpret and you need to go by symptoms.

The current UK guidelines don't really cover this but they do state that retesting isn't necessary after loading doses.

Functional B12 deficiency is recognised as a symptom of various conditions that will result in raised serum B12 levels (eg kidney and liver conditions)

This article may be of some use in making your GP aware of this

The easiest way to manage the risk of a functional B12 deficiency is to keep B12 levels really high - meaning more frequent injections.

Guidelines in the BNF in the UK have recently been amended to reflect maintenance doses on 8-12 week period in the absence of neurological problems and 8 weeks in the presence of neurological symptoms. Sounds like this would probably work for you.

What is the dose of B12 that you have been given.

High dose (1000mcg +) can help some patients who have B12 absorption problems maintain B12 levels but they don't work for everyone and they won't be very effective at raising serum B12 levels in these patients so it may be a waste of time and money.

Your MCHC is still a bit high which could indicate that your red blood cells are still rounder than they should be and that you may still have macrocytois going on - which would be consistent with a functional B12 deficiency.

Loys of people have similar problems and end up self injecting - see replies by beginner1 and wedgewood.



I agree with Gambit62. After injections, your serum B12 comes out deceptively high, but your condition is still there, meaning that your cells have not healed yet. You should consider B-complex injections as you might have other nutritional deficiencies. Also try Centrium or even better, try a sublingual multivitamin and mineral supplement. The one I will be using is Xtra Protecta Sublingual Multivitamin and Mineral. I ordered them from If you live in the UK go to Thank God I have been feeling a little better.

God bless you and hope you get better.

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