Please or to access all these features

General health

Mumsnet doesn't verify the qualifications of users. If you have medical concerns, please consult a healthcare professional.

Severe B12 deficiency - what do I do?

83 replies

WeMeetInFairIthilien · 03/07/2026 14:54

Looking for advice on what to do, I can't think straight.

Went to the GP 2 weeks ago, with what I thought was perimenopause symptoms (brain fog, tired, heavy and unpredictable periods). Also, really bad bruising.

GP ordered a full raft of bloods, had these done on Tuesday.

I'm feeling worse over the last week. Dizzy, nauseous, headache, so, so tired. Heart rate has been dropping to 52 bpm when I'm sitting still.

Ferritin levels came back abnormal (29 micrograms/l).

However, the B12 levels are the biggest concern.

71 ng/l.

Deficiency is at less than 145 ng/l

This suggests I'm severely deficient, especially with my symptoms.

What do I do? My GP surgery, when I phoned, just said that my GP would be next in tomorrow and would review the results, and might get in touch.

Do I wait to hear? The recommended treatment is immediate B12 injections. If I wait, there may be a delay until Monday or beyond with the GP.

And I feel awful - tingly lips, headache, dizzy.

Have got to small children that need collecting from school soon.

OP posts:
KatyMac · 27/08/2026 22:13

Factors that can affect total or active B12 test results
1.3.8
Use caution when interpreting the total or active B12 test results of people who are:
already using an over-the-counter preparation containing vitamin B12 (including vitamin B12 tablets, injections, or transdermal patches), because this may increase total or active B12 concentrations without fully treating a deficiency

taking the combined oral contraceptive pill because this can lower total B12 concentrations without causing a deficiency (however, low total B12 concentrations may still mean the person has a deficiency).

From NICE guidelines

Recommendations | Vitamin B12 deficiency in over 16s: diagnosis and management | Guidance | NICE

https://www.nice.org.uk/guidance/ng239/chapter/recommendations#over-the-counter-preparations

WeMeetInFairIthilien · 27/08/2026 22:31

So, my last B12 injection was 6 weeks ago. I'm curious to see what the levels are, but am expecting them to be still elevated.

The intrinsic factor, ferritin and coeliac results are the ones that I'm particularly interested in.

OP posts:
KatyMac · 27/08/2026 22:38

Are you taking methyl folate or just folate? Magnesium and potassium too? How about ubiquinol? they all help

Sunshineandrainbow · 27/08/2026 22:43

Interesting I went to the GP with ?HRT symptoms and now waiting for B12 injections!

Did you feel better quite quickly?

KatyMac · 27/08/2026 22:45

I didnt but Id been low for years

Thanks for the reminder @WeMeetInFairIthilien I was feeling crap and worked out its been over 2 weeks since I injected, no wonder I was feeling pants

WeMeetInFairIthilien · 27/08/2026 22:46

My folate levels are very good anyway (18.9, upper normal limit is 20.0).
Potassium is 4.6 (right in the middle of the normal range). I have a magnesium supplement with my Vit D.

The evidence for CoQ10 is limited, certainly in the supplementation for anything other than heart failure or migraines.

OP posts:
KatyMac · 27/08/2026 22:58

Thats interesting I take ubiquinol for the same reason I take methyl folate - but Ive been taking both for over a decade and my meno brain cant remember why!!

I am aware when I run out or forget to take but I think they were for mitachondrial and neurological def not anti aging

I also have IBS, ME/CFS & hyper mobility so it could be one of those

Im pretty good at checking if they work for me

KatyMac · 27/08/2026 22:58

VUt D was the most massive improvement with B12 after that

New posts on this thread. Refresh page