Back in 2004 I tested low for B12 and had 6 loading doses, no follow up treatment. Then in 2018 same feelings of fatigue, tested low again (140) and again had 6 loading doses but again no follow up. As I hit 60 (but considered myself very fit for my age as always been keen sports person) I put fatgue down to simply age. Asked again for B12 blood test and surprise surprise as Cilla sang, I tested low again (150). This time and with greater on line resources now available I wasn't prepared to follow same path so I engaged with PAS / B12 Society and took control of being confident to discuss treatment plan with GP. Problem being my Practice is a teaching practice and so you often get student GP or never see the same GP twice so continuity is an issue, however this was not going to put me off!. I received my 3rd lot of loding B12 in May and was then told to wait 3 months for next blood test to see results. Why I nearly shouted, they will probably be high after the doses Duh! So I had the blood test last week but took my last 4 vials of B12 with me and insisted after the blood was taken that I get a maintenance shot which was duly given and GP agreed to then agree a 3 month maintenance dose, however if I feel symptoms returning I will simply book an earlier appt. So that's up to date.
The issue I have is that at the blood test I asked for a) IFAB which initially declined, as I have had one only 3 months ago. I challenged this with the knowledge that its 50-60% inaccurate and so I wanted a number of tests to confirm any diagnosis accurately. Agreed. b) ACTIVE B12 test alongside SERUM B12 - but was advised this was not one of the "choosable options" available so I couldn't get this.
Yesterday my results are on line and are confusing. B12 is reported back as PLASMA B12 ( > 128 - Abnormal - Range 51 -128) and not SERUM B12.
This reported as pmol/L, previous tests reported mmol/L.
Regards IFAB, my recent test showed as 0.5 U/mL (test range < 7 NEGATIVE) and previous tests 11/5 showed at 5.0 (negative) but reported in iu/mL so again a different reference scale.
Same GP, same nurse etc so why are different reference ranges utilised as its most confusing and doesnt help with any anxiety about being on top of a possible life long treatment plan.
Why can we not get consistency in reporting so a comparison with previous results can be made???
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Sailing63
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I have no idea to your questions so I await with great interest to further replies!
Great that you are part of the PA team now as taking control of our health is the only way to go because if we don’t, no-one else will. I call it rowing your own boat!
The PAS is an incredible organisation whose generous members have transformed my life. Like you I am generally in good physical condition - just the bloods need to be tweaked regularly!
Cheers wwwdot. I am of an age whereby bank managers and dr's were treated with great reverence, and whatever they said was sacrosanct.!! Now with many GP's that are younger than me (same as policemen etc!!) I am happy to let my maturity and more importantly research and self preservation speak for me! It would be great if GP and I were more engaged as a team, which to a lesser extent I do feel we are, but different reporting ranges doesnt help as it simply prompts more questions and time with GP to understand.
I am sure that as I and others stay on this best health journey we will become more educated and hence able to engage on an informed and determined basis.
Nurse told me she couldn't request Active B12 test as it wasn't a selectable option. I just take it that from being 140 score on old scale and hence deficient I am now >128 on the new scale so "topped up" . Not sure on IFAB score but again it's a 2nd negative so taking that as not PA. This could mean that supplementation could be via tablet rather than IM, but I will wait and see before deciding on that route and solution
"Yesterday my results are on line and are confusing. B12 is reported back as PLASMA B12 ( > 128 - Abnormal - Range 51 -128) and not SERUM B12.
This reported as pmol/L, previous tests reported mmol/L."
51-128 pmol/L is an active B12 range, not serum. They appear to be confused. Now the question is whether they:
(a) performed a serum B12 test but accidentally shoved the result into a serum B12 result field while providing the active B12 ranges.
or
(b) performed an active B12 test but accidentally shoved the result into a serum B12 result field while providing the active B12 ranges.
B12 results, whether serum or active, to my knowledge, are never provided as mmol/L, either in the UK, US or Europe. They are generally going to come in pg/mL (US) or pmol/L (UK/Europe).
And so the mystery deepens! I have rechecked my original B12 score from April (160) and it is recorded as Serum B12 and in ng/L . Recent score is definitely in pmol/L.The practice nurse did show me on her PC that she wasn't able to request Active b12 but perhaps she didn't understand that Plasma B12 test was same or similar. A call to surgery is my next step. Thanks all.
In fact, many publish a Pathology Handbook (or similar) online and it might explain without the possibility of, umm, any disagreement with your surgery.
Thanks all I will contact surgery to get clarity. Based on Cheryclaire calculations then 128 pmol equals 172 mmol so still below the 200 threshold 8 weeks after finishing loading doses, however I see my result is >128 ie greater than 128 with no actual specific level quoted. Again, standardised reporting would be so much easier for all but perhaps the confusion started at the point the nurse was unsure and unclear on what she requested. Goes to show how B12 still not well understood by many which is surprising when I read so many become deficient as our population ages.
Scientist, not medic, but I did these tests. Some definitions are called for here. This is going to ramble on a bit. You have my permission to put the kettle on before you start reading it.
Pico moles and Milli moles: it's mathematics. The prefixes indicate the order of magnitude.
A molar solution is the molecular weight, expressed in grams, dissolved in a litre.
A millimole is a thousandth of that. A micromole is a thousandth of a millimole. A nanomole is a thousandth of a micromole. A picomole is a thousandth of a nanomole, a femtomole is a thousandth of a picomole. It's just the way we work, to avoid using huge numbers.
Blood comprises two main parts [well, there's many more, but] Cells, and Plasma. The plasma contains the clever bits that cause it to clot. If it doesn't clot, there are two parts: Cells, and Plasma, when we centrifuge the sample. When plasma has clotted, then there are two parts remaining. The fibrin clot, and serum.
Many blood tests are performed on plasma; some are performed on serum, and some are done using 'whole blood'. The FBC is performed on whole blood. If the sample isn't mixed carefully and thoroughly, BUT NOT SHAKEN [sorry for shouting] then the FBC result isn't worth the paper it's written on. Coagulation tests are performed on plasma; the INR for Warfarin control is an example. These different sample types are why we use a multiplicity of sample tubes.
Units [U] versus International Units [IU]: Units are arbitrary figures, International Units are clearly defined, and for that we need an agreed 'standard reference preparation'. To have a result reported in IU it must refer to a reference preparation. If there isn't one, then we can use Units, but not IU. Just because your sample is sent to your local hospital, it might not be tested there. Some of it might be sent to another [reference] laboratory, so that's why the results don't all come back together.
Some patients with 'PA' never develop Intrinsic Factor Antibodies, or perhaps 'detectable IFAb'. So, the approx 50% who test negative despite clearly having all the other parts of the jigsaw are 'IFAb negative' and simply endlessly repeating might not get you what you seek. Some patients, early in the 'disease process', may develop IFAb but it might take months, years, or never. This does NOT mean that earlier results were 'wrong'. They were simply 'negative', or 'not sufficiently positive' to be classed as such. The tests we use are not as clear and precise as we'd all like. Imagine an old radio. Turn it on, and if it's not on the station, it hisses. When we tune it in, the hiss disappears, and the signal is amplified. That's about the 'signal to noise ratio'. Background 'noise' in the test system is just that. Noise, not signal.
When we assay B12, we separate it from the transport proteins, the 'Transcobalamins'. the B12 is chemically bound to them, but by either heating or treating with chemicals, they're freed from the binders. So, then we have 'total B12 in the serum sample' otherwise known as 'serum B12'.
'HoloTranscobalamin' is the carrier protein that yields 'active B12' and it's around 1/4 of the total. That's what's being measured in Active B12 or HoloTC. It's very different from total B12, and hardly surprisingly the numbers will be different.
It's vital when talking about test results that the reference range given for the test is included with the result. Otherwise it's difficult to interpret. No, it's impossible. The tests are done using a wide variety of equipment, so results and ranges vary. We do however participate in External Quality Assurance, as well as running huge quantities of Internal QA. so it's possible to compare results from different labs using different methods, but it's not simple.
Sailing63, please understand the “machines”. Very recently, I ordered a taxi to attend a meeting. I was given Options of 1, 2, 3, 4 of various locations that I had been collected from on previous occasions that I had been collected from. Then the automaton gave me options of where they were going to deliver me. Needless to say, after hearing the 1st option, I swore at the robot. It is a piece of Artificial Intelligence and has no feelings.
If you really know about this disease, most of us look after ourselves. Keep a symptoms diary. Treat ourselves. Someone is undertaking some research regarding ‘Why some people have to inject more than others by testing urine.’ Although, if I ran a marathon which is 26.2 miles one day and sip water throughout the 3 hours 32 minutes it takes me; I might only void 500 mls for the rest of the day. I undertook that on a bright cold day in April, and the clocks were striking thirteen when I finished my run. Now, had I ran at the same pace in a heatwave, my need for water, B12, iron, magnesium, calcium, electrolytes of sodium and potassium etc are greater.
The younger doctors are really believing what the machines are telling them. They honestly think that it is gospel. Sadly, they too have been programmed.
😈 = daemon
(Lots of Linux or Unix utility programs use it to do stwff simultaneously)
You can find calculators on-line that can convert between units. The ranges for normal for some tests vary between labs- sometimes it is a difference in how the tests are done, other times (like an acceptable B12 level) there are differences in opinions with regards to how low is too low. I don't understand why they are testing your B12 levels after you have had injections. The advice is to not test because it can come out high but not because of anything wrong with you: it is because you are supplementing. To me, the units/comparisons for your tests are not the issue. If you have B12 in your diet but keep going low, then to me, that is the critical information that should be used here.
From the number of times you have relapsed and needed loading doses again, I think it is a reasonable assumption you have PA like the rest of us. The absolutely critical thing is to continue treatment for the rest of your life. It is not good for you to relapse before restarting. Some people with PA seem to do OK with injections every 3 months. Many people on this forum are not. Many result to self-injections to ensure they get the amount you need. It would be good to monitor symptoms to figure out how often you need injections. I get tingly toes back in about 3 weeks so I get my husband to give me an injection once per week. You doctors seem to be missing the point that if you have PA, you need treatment for life. I don't understand why they keep giving you loading doses with no follow up treatment. Unfortunately, the test as you mentioned is not reliable for diagnosing PA because there is a high false negative rate. It's nice that they are willing to give you an injection sooner if you need one sooner. I find though it is so much nicer to not have to make a trip to my doctor to get an injection. Very best wishes.
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Are my symptoms consistent with B12 deficiency especially burning sensation. 
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