Pernicious Anaemia Society
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Borderline B12

Hi, I was wondering if I could get some advice please. I was referred via Bupa to a haematologist for a persistent raised lymph in my neck. The ultrasound & lack of other symptoms means they are not concerned about the lymph however I got my blood results today. My full blood count from the GP was ok but the bloods taken by the heamatologist show serum folate 3.7, B12 178 which he describes as borderline low & recommends further test in 3 months.

Can anyone explain what this means? Where on the internet can I find the recommended levels? Any advice greatly received. Thank you

6 Replies

The main thing it means is that the specialist may be a specialist haematologist but they probably aren't a specialist in B12.

Blood tests will come with reference ranges - this is because the ranges depend on the sensitivities of the assay methods and the pieces of kit that are used - you will be entitled to a copy of the print out of the results.

B12 serum isn't a test that can be interpreted purely on the basis of results but needs to be evaluated on the basis of clinical presentations - ie the symptoms. Some people will be perfectly fine at the levels you have - others most definitely won't. People vary a lot in how they respond to B12 and how much they need so reference ranges - which are based on statistical averages - aren't something that can really be used to say if any given individual is okay.

You can find a checklist of symptoms here


check them carefully - you may have symptoms but have put them down to other things like getting older or stressful periods in your life.

Were you asked about your diet at all- B12 is only found in meat products so if you don't eat any meat/fish/dairy/egg then you will slowly become deficient and levels will drop over a period of time ... but it can take decades.

However, more common for a B12 deficiency to be the result of an absorption problem - of which PA is one possibility. Usually the symptoms start to snowball as your levels get low.

There are some tests that can clarify if there is an underlying B12 deficiency - MMA and homocysteine.

Hope this answers your question a little bit.


Thank you. I was weirdly disappointed that my initial blood test by the GP showed iron levels as normal as I'm always so tired and wanted there to be a reason. My libido is non existent as well - I am 45 and have been suffering these two main issues for years so just thought it was me. Now I'm beginning to think it may be down to B12.


haemo may have been looking for signs of macrocytosis - red blood cells slightly enlarged and rounder than should be which is a classic sign of B12 deficiency. However, this can be masked by high folate and/or low iron. Also this isn't a defining characteristic of B12 deficiency and other symptoms develop first in at least 30% of cases. The effects of B12 on blood aren't the only ways a B12 deficiency can cause the symptoms you mention.

Suggest you start by asking for a copy of the blood test results and try posting here with ref ranges

also read through the pinned posts

you might want to think about getting an earlier appointment when you feel you have managed to get a grasp of how B12 works and possibly writing to the consultant beforehand with some key facts ... or look to working with GP.

Important not to supplement before you have exhausted all the testing possibilities



I 'd recommend reading/searching the following for more B12 info

1) BCSH Cobalamin and Folate Guidelines

UK Document that outlines diagnostic process and treatment for B12 deficiency. click on "Diagnosis of B12 and Folate Deficiency"

2) BMJ B12 article

3) Pinned posts on this forum

4) Book "What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper

5) Book "Could it Be B12" by Sally Pacholok and JJ. Stuart

6) PAS (Pernicious Anaemia Society) website.


7) B12 Deficiency Info website


I am not a medic just someone who has spent years trying to find answers to my health problems.


If you live in England then the NICE recommendations class a B12 level of 170 or below as having low vitamin B12 the main count you need to get done is your ACTIVE vitamin B12 levels! I had to pay for mine privately, but were taken by my local hospital and send to St Thomas in London with results back to me! If you have an active B12 level of 50 or below then you need B12 injections urgently!


Thank you all for your replies. I will do lots of reading up on this, write to the consultant who took the tests, and request further testing in 3 months.

My only symptoms appear to be tiredness and short term memory not as good as it was. I do appear to also be more sensitive to cold but I'm not losing weight (quite the opposite actually!). Thanks again - if I manage to get my blood tests I will post them.


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