Blood Test Results - Please Help - Pernicious Anaemi...

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Blood Test Results - Please Help


I'm currently being investigated for Coeliac Disease and, as part of those investigations, was diagnosed with iron deficiency anaemia last year. My blood test results also showed a B12 level of 340ng/L.

I'd been taking the BetterYou B12 oral spray (240% EC NRV) for 12+ months. I contacted the B12 charity here in the UK and was advised that the supplement was "masking" a B12 deficiency.

I increased my supplement intake (Solgar Methylcobalamin 1000mg, 1-2 sublingual tablets a day) and, when I had blood tests in April because I was feeling improved but still not at my normal energy, my B12 was 1087ng/L.

My doctor told me to stop taking the supplement. In the seven months since then, I have slowly become more unwell and symptomatic:

- exhaustion (tired doing small things like washing my hair, reaching top kitchen shelf, etc) to the point of being bedbound;

- feeling smothered in my heart and brain as though they are not getting enough oxygen;

- breathlessness;

- tingling in my hands and feet to the point of pain;

- hair loss;

- forgetfulness;

- a twitch in one eye;

- irritability.

These are the same symptoms that I experienced last year when I was told that I was "masking" my deficiency and so I began to take B12 supplements again.

I've taken Jarrow Methylcobalamin 5000mg (one tablet each day) for the last five weeks and my strength has improved enough to get to my GP for blood tests.

The results show a B12 level of 1059ng/L. My serum folate is 7.9ug/L. My serum iron is 11.6umo/L.

My doctor asked if I had ever had B12 injections because my level was so high. I told her that I hadn't had injections, but that I was taking 5000mg a day.

She couldn't tell me (1) how the supplement affects my results or (2) what my 'true' B12 level might be.

Can someone please, please help? Is it possible that I have a deficiency that's being hidden by my supplements? Are my symptoms consistent with a deficiency?

I'm happy to give any other blood tests results if they'd help.

Thank you.

2 Replies

Ignore the idiots from that B12 charity.

How on Earth is it possible for B12 supplements to ‘mask’ a deficiency? The supplements are either getting absorbed, thus fixing the deficiency, or they’re not getting absorbed, and aren’t masking anything.

You were taking supplements. They reduced your symptoms. There’s one obvious conclusion - keep taking the supplements. If they do a good job of making you feel OK again then that’s all that really matters.


Unfortunately there really is no way of knowing what the right level for you is now that you have started supplementing. The normal range is a very large range and people sit at different places in that range.

Whilst you seem from what you describe, to have an absorption problem, about 1% of B12 (that's an average and there is a huge variation) is absorbed outside the ileum so taking high dose oral/sublinguals can result in enough being absorbed. 5000mcg represents about 1000% RDA, so that means you would be absorbing about 10x RDA from one tablet - so could raise your serum B12 levels.

Oral doesn't work for everyone but it does seem to work for you - so suggest that you stick with it if you are feeling better.

Its less efficient at raising B12 levels than injections but if it is working, suggest you continue.

Supplementing can mask an absorption problem by using 'passive absorption' to maintain B12 levels. passive absorption isn't very efficient at raising levels so it for some individuals it could be sufficient to keep B12 in the normal range but not to raise it to the point in the range that is correct for you.

Serum B12 is a good test for identifying an absorption problem in the absence of supplementation as the absorption problems will cause a drop in your B12 levels - so a single point in time isn't necessarily that helpful unless you have already become significantly deficient.

Symptoms are probably the best guide to deficiency but the overlap with the symptoms of of other conditions makes symptoms rather difficult to use as a diagnostic technique. However, the fact that your symptoms improve when you take B12 and then get worse when you don't is a good indicator that B12 is involved in some way.

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