Hello, i had an endoscopy December 2024 to check how my celiac disease is now that i have been on a gluten free diet. I had biopsy taken and while waiting for the results my GP had IFAB and Parietal cell anti body test done. Both have come back negative. I also had B12 serum test done which came in at 225 and folate at 1.5. My GP said this was fine which of cause it wasn't so I purchased my own set of tests. B12 active came in at 58 pmol/L and MMA high at 54.0 ug/L which does suggest B12 deficiency and according to NICE would mean I should be having B12 injections. However, my GP once again said my B12 was normal according to the NHS guidelines.
I was looking at going down the route of self administering via Dr Klein of CluB-12 but i then read something about supplementing B12 can increase Hemoglobin and Haematocrit both of which are just outside of the normal range depending on what levels you look at. So, i paid for some further tests and my MCH was found to be above normal. These are my results:
Result Range
WBC - 7.7 4.0 - 10.0 10*9/L
RBC - 5.13 4.50 - 5.50 10*12/L
Hb - 173 130 - 170 g/L
Hct - 0.51 0.40 - 0.50 L/L
MCV - 99 83 - 101 fl
MCH - 33.6 27.0 - 32.0 pg
Platelets - 214 150 - 410 10*9/L
RDW - 12.9 11.6 - 14.0 %
I am baffled now and not sure if I can safely supplement B12. However, I have read something about Macrocytosis and elevated MCV pushing up Hb and Hct.
Can anyone comment on the above and offer any advice please? I really would like to start self administering B12 but obviously do not want to cause myself any further harm.
Thanks
P.S I have hereditary hemochromatosis and my GP is also testing for pancreatic insufficiency via a stool test.
Written by
bflare
To view profiles and participate in discussions please or .
It looks like your MCV is high. This can indicate B12D. Given your serum B12 count, this indicates you could have difficulty absorbing B12. PA is an absorption condition.
I'm under an haematologist for my hemocromotosis who I have contacted regarding the B12 subject. However, he then passes me back to my GP who he says needs to refer me back to him if he thinks there is a need. My GP thinks my B12 is fine as I was given folate which pushed my Serum B12 up to 495. Plus because my IFAB and Parietal cell anti body test came back as negative he told me to supplement with B12 tablets. This is why I have reached out to Dr Klein of CluB-12 who straight away said i'm deficient given my MMA and active B12 results.
Yes i found this very frustrating to be honest. I am having to source most of my tests privately as my GP is passing everything off as normal when it clearly isnt!
A quick google revealed Dr Auwerda. I'm assuming this is the gentleman in question.
Scientist, not medic. I'll try picking away at these!
Your Hb is just above the top of the range. The range is a 95% range, and this means that 95% of 'normals' [whatever they might be] will be within that range. Meaning that 5% can be outside that range whilst still being normal. So you're just in the upper end. [Is there any chance you could have been dehydrated when the sample was taken? That could nudge the Hb up.] Your MCV is normal. [Alcohol consumption can cause an elevated MCV; is this possible?]
Folate looks to be on the low end; folate isn't stored in the body, so regular intake is required. B12 looks normal.
Supplementing B12 can cause an increase in Hb but sensibly, in a deficiency state. It's unlikely that you would respond that way in your case.
As for supplements, then iron needs avoiding, especially in your case.
As Lance Corporal Jones would say in Dads Army, 'Don't Panic!'
Listen to your GP. They're not always right about everything, but it's a good place to start.
I'm not a medic but I am an engineer so i love research!
According to various papers the upper reference limit for MCV quoted varies from 95–100 fL therefore, at 99.83 i could be seen as having abnormal MCV. I could in theory fit the criteria for Macrocytosis without anemia. A lack of vitamin B12 can cause macrocytosis. Macrocytosis as been seen to contribute to elevated hemoglobin and hematocrit levels thus mimicking a diagnosis of polycythemia vera. According to this.......
Because the size of RBCs (MCV) determines the Hb content of RBCs (MCH), the higher the MCV/MCH, the higher the Hb and vice versa. Similarly, MCV is a principal contributor to Hct because Hct is a product of RBCs of certain sizes: Hct = RBC × MCV. This classic formula not only demonstrates how Hct is calculated (manually or by cell analyzers), but it also exposes the fact that MCV is as important in determining Hct as RBCs.
My MCH is also above normal limits. Unless I am completely off the mark my just above normal Hb / Hct could be due to my borderline MCV / MCH. More importantly this would suggest that B12 injections wouldn't push up my Hb / Hct further and could possibly help to reduce them to normal.
Regarding dehydration. I did make sure i was hydrated 48 hours before the test and prior to the test. I gave up alcohol 6 years ago. However, prior to this i did drink alcohol alcoholically for 25 years!
You seem to have a good understanding of what we do in haematology laboratories and how we make up stuff to report. Depending on the manufacturer of the analyser, then the MCV range can vary a bit.
Generally speaking, macrocytosis is a product of megaloblastic change in the bone marrow, and once more, generally speaking, megaloblastic bone marrow can result in shorter red cell life and therefore increased red cell turnover. It's unlikely that you'd see a rise in Hb due to B12 lack [in my understanding] because the erythropoiesis is bordering on the ineffective; MCV up, MCH up, but RBC down and Hb down. The MCV is measured directly, in all of the current haematology analysers [but don't get me started on that one] and the MCH is derived from RBC measured directly, and the Hb is measured directly. The RDW is a reflection of the distribution width of the red cells; any change up or down in the MCV sees the RDW increase. Yours is normal.
Yes, from my understanding MCV used to be calculated many years ago but now its actually measured and the Hct is calculated from this RBC x MCV / 10.
In my case 5.13 x 99 / 10 = 51 Hct. Therefore, where the Hct is concerned it would make sense that this could be elevated as a result of the elevated MCV. Thus, supplementing with B12 could lower the MCV which in turn would lower my Hct. Is this correct or am I way off with my assumption?
FlipperTD "It's unlikely that you'd see a rise in Hb due to B12 lack [in my understanding] because the erythropoiesis is bordering on the ineffective; MCV up, MCH up, but RBC down and Hb down." Do you mean that you believe that I shouldn't see an additional rise in Hb if i was to supplement with B12?
You're spot on. The calculated MCV required a spun PCV and that has artefacts, mainly trapped plasma between the red cells in the centrifuged sample, so the PCV as measured was over-estimated by a small percentage, but varied dependent on the shape of the red cells. Spherocytes pack best in a centrifuge, and microcytic hypochromic cells seen in iron deficiency pack worst. Technically, there are ways of measuring trapped plasma but that's a lesson for another day.
The calculated MCV also required a red cell count, and that came with a big margin of error. In a counting chamber with a microscope, the errors are such that it's not worth trying. With a particle counter requiring manual dilutions, that was better, but still had large errors. The development of the Coulter Counter Model S had a splendid dilution system, a good counting system and a reliable MCV measured direct, so all of a sudden the calculated Hct became far more relevant.
As you can probably guess, I could go on [and on, and on] about this, but to retain everyone's sanity, I will avoid doing so.
Because MCV elevation is common and frequently occurs without anemia , the described clinical effect of macrocytosis is more prevalent than generally
appreciated. Moreover, the impact of MCV on Hb/Hct is by no means trivial. The observations demonstrate that the effect of a 10 fL-change in the MCV value on
the total Hct approximates a change of 0.5 × 106/μL in the RBC count. The recognition of RBC count equivalent of MCV explains the capacity of MCV to force Hb/Hct beyond the normal levels even in the absence of high RBCs. And, vice versa, it shows how even borderline MCV (<100 fL) can cause abnormally high Hb/Hct. Such cases, if unrecognized, could be incorrectly interpreted as polycythemia vera. For the rule of dynamic equilibrium to work, accurate RBC and MCV measurements are mandatory. Spurious macrocytosis and spurious erythrocytosis will predictably cause a wrong interpretation.
The diuretic use caused the loss of water. This reduces the blood volume, but it's only plasma fraction that's being reduced. That's causing the Hb to appear to be raised. As the Hb rises, so does the PCV, because that's where the Hb is. The MCV is largely a bystander in all of this, although it's mildly elevated. The statement of the combined effect is true, but it's the diuretic that caused the phenomenon. MCV elevation is typically considered to be due to megaloblastic change, but it can also be found variably] in alcohol consumption, and also with thyroid problems. It took them quite some time to arrive at the conclusion!
But as FlipperTD says, you should get folate in your diet every day as a folate deficiency causes many of the same problems as B12 deficiency so you don't want to draw down reserves into the danger zone there either.
I'm wondering where the stores of folate reside in the body, and the 'four months' statement makes me think it's probably in the red cells. They are replaced every four months [well, not every four months in a big batch, but you know what I mean!] Red Cell Folate is a far more reliable measure of folate status [if the lab offers it, as it takes another step or two to do it, and at least one major manufacturer's folate method is rubbish for red cell folate.]
To answer the title of your post, B12 supplementation is safe at any dosage. No tolerable upper limit for safety has been set. In terms of injections, reasonable safety precautions should be followed which you can readily find here.
To answer the title of your post, B12 supplementation is safe at any dosage. No tolerable upper limit for safety has been set. In terms of injections, reasonable safety precautions should be followed which you can readily find here.
Thank you. The title of my post is a little misleading now I’m looking at it. What I actually meant was is it safe to supplement B12 when you have hemoglobin / hematocrit already on the high side. I’ve read that B12 supplementation can increase hemoglobin / hematocrit however, given my recent research regarding MCV I’m now thinking when MCV is high then supplementation of B12 may actually help lower hemoglobin / hematocrit.
If you were anaemic from B12 deficiency, B12 supplementation would lower a high MCV (because it corrects macrocytic anemia) and raise a low hemoglobin/hematocrit (due to red blood cell production increasing to replace the defective ones). We now know that less than 20% of those with B12 deficiency have anaemia (ref: pmc.ncbi.nlm.nih.gov/articl... )
If you're not anaemic as a result of B12 deficiency, none of these things would be expected to happen and B12 likely would have no significant effect on your hemoglobin and hematocrit.
From this study : pubmed.ncbi.nlm.nih.gov/322... we know that once B12 gets into a healthy range, hemoglobin does not continue to increase.
I am not clinically trained but I can't think of a situation in which supplementing or injecting B12 would be unsafe, regardless of your hemoglobin/hematocrit. It doesn't affect these values in a mechanical way but secondarily, as a result of fixing a dysfunctional situation which may exist as a result of B12 deficiency.
When a nutrient has no tolerable upper limit set, it means that, in a comprehensive survey of the medical literature, teams of nutrition experts who aim to set these values could not find any evidence of harm from excess B12 in any circumstance. These panels are quite conservative and operate on a precautionary principle if any evidence is found. For B12, there has never been any verified reports of harm if you discount a tiny number of allergic reactions which could be related to some particular formulation/impurities or contamination.
The biggest concern with B12 supplementation is that it tends to elevate B12 to the extent that getting a B12 deficiency diagnosis or testing for PA may become difficult to impossible since many physicians will take one look at the elevated serum B12 and send you packing. Delaying injections or supplementation becomes impossible due to the return of symptoms so the chance for a diagnosis (and treatment on the NHS or your local health service) is lost.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
MCH MCV relation to PA or B12.
Advice on B12, MCV and MCH please...
why s mch rising now asI am SI daily??
MCV 95.3 fL and MCH level 32.2 pg (27-32) but gp refusing trial of b12 injections
