Most Accurate B12 Blood Test Please? - Pernicious Anaemi...

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Most Accurate B12 Blood Test Please?

Blondie503 profile image
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Would you tell me what the most accurate B12 blood test is please?

I've had the serum test and been told my levels are too high for me to be deficient but I feel so fatigued, have joint and muscle pain, headache, blood shot eyes, insomnia, white finger nails and a banging heart.

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Gambit62 profile image
Gambit62Administrator

what were your levels and what were the other blood tests that were done.

Unfortunately there are a huge number of conditions that can cause the symptoms you mention and B12 deficiency is only one of them. Thyroid would be another possibility but there are also others.

Ranges and variation for B12 are quite wide meaning that all the tests are quite limited. Active B12 has a narrower margin of error but they all need interpretting in context and it is often easier to rule out other conditions ... though there are also some significant problems with the way GPs look at tests and read results.

Both serum and active B12 are looking at the amounts in your blood so are reasonably useful for assessing an absorption problem - but that's difficult from just one point unless the deficiency is quite advanced - significant downward trend over time is more useful for identifying a deficiency before it gets to an advanced position.

However, have to come back to the problem of your symptoms being rather broad and potentially due to a large number of conditions.

Blondie503 profile image
Blondie503 in reply to Gambit62

I'll look at my blood tests again. I've had so many. I was thyroid blood tested when all this first started but not sure if it was advanced testing. I can't think of what they are called. Sorry no energy. T3 and T4 I think?

My serum b12 report says "0.12 less than 0.29 does not indicate B12 deficiency". The problem is, i started B12 spray and oral supplements for sometime prior to the test. I came off them a month before the test but think my whole blood levels were still high.

In the past, when the banging heart started, I'd spray b12 and it would normalise within a couple of minutes. B12 spray also helped reduce all my other symptoms. It helped my insomnia. Went from 4 hrs to 6 hrs sleep, more energy, less joint and muscle pain, more clarity of thinking. I've had to come off it again for a b12 active test. I stopped b12 spray a week ago and symptoms have got steadily worse.

I'm concerned I'm going to get stuck in this cycle of feeling dreadful with no end because I've got all this supplemental b12 in my blood and I get another "normal" results.

Thanks Gambit62

Gambit62 profile image
Gambit62Administrator in reply to Blondie503

I think the result you are quoting is actually IFA (test for PA as a cause of a B12 deficiency) rather than serum B12. A negative is a long way from proving you don't have PA though as the test isn't very sensitive.

Suggest you actually get a print out of the test results rather than trying to remember things.

Unfortunately it takes at least 3 months without supplementing to get to a baseline for b12 so you are right that the supplementation is affecting things.

Blondie503 profile image
Blondie503 in reply to Gambit62

I've got a b12 active test next week. Do you think I should put it back 3 months?

Blondie503 profile image
Blondie503 in reply to Gambit62

I've got print outs of all my tests. It says "methylmalonic acid - serum 0.12. Less than 0.29 does not indicate B12 deficiency."

I don't understand the figures compared to what other people have posted either.

Blondie503 profile image
Blondie503 in reply to Gambit62

I've checked and MMA serum they've done is just a marker for B12. That's why the ranges were confusing me. I was given the impression I was having B12 serum test.

Apologies for the 3 replies.

Gambit62 profile image
Gambit62Administrator in reply to Blondie503

MMA isn't a common test to get done. Generally it is really high if your B12 is deficient so it sort of makes B12 deficiency unlikely as an explanation.

MMA is a waste product that builds up if your cells don't have enough B12 to recycle it - however it is also likely to be quite responsive to supplementation.

If you are paying for the test then you'd probably be better saving your money and not having active B12 done at this point

Blondie503 profile image
Blondie503 in reply to Gambit62

Thanks Gambit62. I feel like I'm going round in a circle while feeling unwell. I wish i hadn't been pro-active with taking supplements. I just wanted to feel better. The lab have said come off supplements 24 - 48 hrs before testing, the clinic are saying 5 days and my GP says 2 weeks. Ive opted for 2 weeks but as you say, this likely won't be long enough. I'm stuck. I can't feel ill like this for 3 months but I don't want to continue getting nowhere with testing.

I don't think it's an intrinsic factor problem. I took very high doses of magnesium for 6 months before the b12 symptoms started, as I was deficient. This was recommended by a Dr who had written a book about magnesium deficiency as I got nowhere with GP. Not their fault, most aren't aware of magnesium serum test's inaccuracy. GP's only have access to magnesium serum test.

I've had red blood cell magnesium test since and I'm deficient.

Ironically, I think the reason I'm magnesium deficient, is because I took zinc for years when someone recommended it (without blood testing). Zinc impedes iron. When i gave blood, the blood people said your low on iron, take iron supplements. It turns out both deplete magnesium!

So i stopped taking the high doses of magnesium when i realised that was the active ingredients in antacids for indegestion and it neutralised stomach acid and i wasnt getting enough neutrients. A bit of a flaw in the book I feel.

if I am b12 defficient because of the above reason and not intrinsic factor, now I'm off everything, will my b12 correct if I use the spray and have a healthy diet? I.e. no injections.

Very sorry for the long question.

Gambit62 profile image
Gambit62Administrator in reply to Blondie503

I don't really feel qualified to answer your question. Whilst PA may be the most common cause of non-dietary B12 deficiency the test for it isn't particularly sensitive so gives false negatives 40-60% of the time. It's very specific so very low probability of a false positive. Basically a negative is a long way from ruling out B12.

The overlap of symptoms with other conditions is so significant that just diagnosis on symptoms is difficult. Its quite difficult with a serum B12 or an active B12 test because of problems with sensitivity as well.

It would be worth clarifying exactly what you are being tested for - folate deficiency is another possibility - and if that isn't dietary then it would be likely that you do have a B12 absorption problem as well. B12 absorption problems are generally irreversible (few aren't such as h pylori infection, tapeworm infection) so possible that you might return to normal if the problem is an infection and that is treated. Otherwise it's unlikely that you would be able to correct a deficiency caused by absorption problems just with tablets - sublingual or not - you just won't be able to absorb enough from the tablet to raise levels - though they can be effective in maintaining raised levels. If you suffer with indigestion that could actually be an indication of low rather than high stomach acidity which would also result in B12 absorption problems and all that has happened is that trying to treat that has made things a bit worse - so you would still have an absorption problem (and potentially one that will get worse over time - meaning growing deficiency).

Sorry - that's a long way of saying that there isn't any clear answer though on the whole I'd say its unlikely you would recover with just the spray

Blondie503 profile image
Blondie503 in reply to Gambit62

Thanks so much for your detailed reply. You raise a good point. I'm also deficient in magnesium, calcium and zinc and just scraping into the low range for chromium, copper and manganese. So i feel a bit crap - hope I can say that here.

All the above were plasma BT's so more accurate than surum. So a possibility of infection or the high doses of oral magnesium supplements impeding stomach acid.

I'm booked for folate along with active B12 next week.

Thank you.

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