Blood tests - High serum vitamin B12, high Se t... - Thyroid UK

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Blood tests - High serum vitamin B12, high Se thyroid peroxidase, low serum ferritin etc - reasons


I am heterozygous (one faulty gene, I think!) on my C677T and A1298C chromosomes, which suggests issues with methylation and deficiency in B vitamins.

I have lots of health issues, just had a uterus polyp removed, I have lots of chronic discomfort and issues with my gut and was diagnosed with small intestine bacterial overgrowth, I have spinal degeneration, I suffer with hypothyroidism.

I went to my GP for blood tests, due to a concern that I might have pernicious anemia (problem with Vit B12 levels.)

There were lots of exclamation marks all over my blood tests, but the GP said everything was reassuringly normal!

I wonder whether anyone can help me to decipher the results?

The most marked anomalies were as follows:

Se unsat iron binding capacity my reading was 76, the normal range is 45-70

Serum vitamin B12 my reading was 817, the normal range is 200-770

serum ferritin my reading was 10, the normal range is 13-150

se thyroxide peroxidase Ab conc my reading was 231, the normal range is less than 34

Haematocritin my reading was 0.361, the normal range is 0.39-0.44.

I read on one of the posts on this forum that a high reading for B12 actually doesn't rule out pernicious anaemia, indeed it could indicate quite the opposite, because it may be that it is an un-usable form of B12, which is building up because it is not being concerted into the use-able form, which is methylcobalamin.

I also understand that the NHS blood tests can be unreliable and that there is a new privately available blood test that looks for something called holotranscobalamin. Does anyone know if this blood test is different from the nhs one because it can check for all the different kinds of vit B12, where the nhs test just looks at B12 without looking at what sort it is?

Sorry this is complicated, but hopefully someone understands and will kindly reply.

Thanks a lot!

5 Replies

it would be helpful if you post all your blood test results not just the ones out of range as blood tests are interpreted in groups.

For example people with low ferritin can often have iron deficiency anaemia but the only way you know that is if they post their full blood count (also called complete blood count). I should add the range used by some labs for various factors is often lower than the WHO or NiCE guidelines which is why stating being in range isn't sufficient.

FreyaMosaic in reply to bluebug

Thanks! I will do that then. Will the readings all make sense to you?

bluebug in reply to FreyaMosaic

The iron once are likely to, and even if they don't make sense to me there are other posters who they make sense to.

Edited to say: you already have someone on the case of your B12. Do you have a folate level to help them?

Referring to your high B12...

Do any of your supplements contain B12? If you've never supplemented B12 in recent years then this paper may be of interest - note it is also available as a PDF which can be downloaded :

If you have supplemented B12 in recent years then a high level is not an issue. B12 is water soluble and the body eliminates what it doesn't need. My B12 is over 2000 because I supplement a lot.

Thanks a lot! It does look like a very interesting paper.

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