"What monitoring is required after treatment for vitamin B12 deficiency has started?
Perform a full blood count and reticulocyte count:
Within 7–10 days of starting treatment.
A rise in the haemoglobin level and an increase in the reticulocyte count to above the normal range indicates that treatment is having a positive effect."
Is this correct, that from 7 to 10 days after loading doses start this blood test should be done?
I have started my loading doses two days ago. The only blood test I have scheduled is next week for the intrinsic factor antibody to try to identify the cause of my B12 deficiency
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Springblossom13
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I’m convinced that very few doctors ever consult the guidelines . You only need to read the posts on this forum to realise that . And if they do , they don’t follow them . My doctors certainly didn’t , that’s why i had to go to a private doctor .
Yrs as long as not out if date lab equipment. As false positives can happen with high b12 in your blood .shoukd be fibe before b12 treatment starts as goid practice.
(Those guidelines could have been written by me, or based on me being overheard!)
Well done, NICE.
The reticulocyte count reflects bone marrow activity, and will show a response within a very few days. Megaloblastic [B12 or Folate] change reacts even quicker than Microcytic Hypochromic [Iron Deficient] change, but even Iron replacement can be seen to be working within two weeks, when following the reticulocyte count. The Haemoglobin level won't move that quickly, of course. The MCV will show change but once again, not that quickly. The RDW will reflect the changes quite soon too.
There is no justification in measuring B12 once replacement has started, especially if the injections are being given by the surgery, as compliance is assured.
In my laboratory, it was standard practice to perform IFAb tests on abnormal low B12 results unless we had a good reason not to do so.
Not only did we test our own patient samples, we also provided a referral service for other labs. Your observation that it would save time and everything else for so many was covered in some of my lectures to others. Reflexing IFAb tests when it's such an obvious solution wasn't entirely popular with some of the hierarchy, by the way! In general if there was enough sample for the B12 assay there would be enough for the IFAb assay.
As you say about the hierarchy though - I can imagine people challenging you as to why an extra test was being done which was not initially requested
I will try taking this up with my surgery. I think the best way is I will ask which lab they use, and go to them direct since at the surgery everybody just does their role, and not want to do anything more proactive to improve the system. Though the lab will be probably be the same.
People are penalised for thinking or acting outside the box
You're absolutely right. The standard approach is for everyone to work by rote, to written procedures, [and that's good]; to do exactly what is asked and not question anything [that's less good]. I could go on about this but won't.
The introduction of 'GP fundholding' whereby GPs would be billed for tests done was a potential problem. If tests were done that weren't originally ordered, the GPs had the right to refuse to pay for them. Did I bother with discriminating? No. Did any of the surgeries try to refuse? Not to my knowledge.
It's much the same in life in general; folks not appreciating the difference between efficiency and effectiveness. 'Doing things right' [efficient] and 'doing the right things ' [effective].
CKS topics are developed by Clarity Informatics Ltd but commissioned and funded by NICE.
For clarification, CKS are not equivalent to NICE guidance as they have not been produced using a NICE process, nor are they signed off by NICE guidance executive.
Topics are written by an expert multidisciplinary team with experience of primary care, supported by a network of over 6000 specialist external reviewers.
Thanks for distinguishing between the two organisations, and highlighting the CKS even exists
Seems like a lot of duplication. Equally I can not understand why every Clinical Commissioning Group (CCG) makes their own guides.
As far as I can see what is written CKS guides agrees with the NICE info for B12. Differences I have seen start to occur at the CCG level, some of which have differing guides to B12
For B12, you might be right. But not for all areas of medicine that are covered.
CKS existed before NICE. At some point, they seemed to move from the generality of the NHS site to being within NICE's own website.
The obvious approach to guidelines, in my book, is to use NICE as the prime source. With lower levels (whether CCGs, boards, or whatever) simply replacing what might be generalities in the NICE guidelines by specifics. For example, spell out laboratories, test tube colours, escalation routes, etc.
Occasionally there will be more significant differences. Such as when a new test is being introduced, or a study is being run, or if results are discussed in terms of nanograms/L then switch to picomol/L if that unit is used locally. One example could be if an area switched over to Active B12. (I think this is common within private testing such as The Doctors Laboratory in London. Just because someone uses a private service, whether for testing or also for treatment, doesn't of itself mean NICE guidelines should not generally be followed.)
Interesting about the units. It is very confusing. Do you know if the NHS has a standard?
Like the UK uses the metric system for most things (except miles), so if I am right this is also known as the IS (International System of Units).
So this is pmol/L for measuring B12
It maybe by chance, but when I had my B12 measured at a private lab (London Laboratory) they used pmol/L . When I had it was done with NHS in London it was ng/L .
When I have seen CCG guidelines it talks about ng/L. NICE page references has at least SI units and ng/L
The NHS and Europe do tend to use SI (rather than IS!). But the flip-flop between molar and mass measurements is inconsistent and confusing.
In the CKS guidance, it seems to give precedence to ng/L (adding pmol/L after) except for "in old age"! Probably just an editing mistake, but it doesn't seem a lot to expect - consistency on one page!
Active B12 is, I think, always in pmol/L - and the Active B12 test is quite common for private tests in the UK.
Unfortunately, for B12, the numeric values of pmol/L and ng/L are similar enough that they don't jump out at you as being one or the other. (Some blood tests have very different numeric values depending on units, and they tend to be more obvious and less likely to be misinterpreted.)
Thanks for that! At times I have certainly wondered about how much excellence there is in NICE, to be honest. Very much like some of the groups and acronyms that have sprung up over Covid. Some seem clinical, some seem more political. But as for reticulocytes after starting replacement therapy for any deficiency anaemia, it gets my vote. Granted, in years gone by, retics lacked precision because they were counted down a microscope, and the inherent errors were [no, best stop!] Nowadays the science and engineering have tended to catch up.
So, Flipper, to confirm do you feel I should request, as per the NICE guidelines,
"a full blood count and reticulocyte count: Within 7–10 days of starting treatment.
A rise in the haemoglobin level and an increase in the reticulocyte count to above the normal range indicates that treatment is having a positive effect"?
Also, in your experience is it ok for me to have the IFAB test done at the same time? i.e. having just started on the B12 treatment
If you've been on B12 treatment for a week or two, then your bone marrow will have reacted and given you a reticulocytosis. (it depends on how the retics are counted, but any method will show a change.) It proves that your marrow is working overtime. The more anaemic you were at the outset, the more spectacular the reticulocytosis will be. The Haemoglobin will be rising, but that's slower. If your anaemia is severe, it's important that you don't 'run out of anything else' whilst you're fixing the primary problem. Iron and folate are things to consider.
There are various other things that can be seen to change too. If the lab reports RDW, then that will show an increase, and it will continue to increase until half-way through the recovery process, and then it'll tail off, and that's perfectly normal. (I could go on, but won't.)
As for IFAb, it depends on the exact method in use, but it should be OK to do during treatment. It would be sensible to include a note on the request that you've started B12 replacement therapy, just in case there's a lab issue. Personally, I wouldn't recommend getting a private test done through a high street outlet, but that'd be your choice.
I have a feeling that my blood results did not indicate anaemia, though no peripheral blood film was conducted to be sure. My fatigue (which has improved since starting supplements) may, as discussed elsewhere in this chat, have been for something else B12 related
Given that I will be having blood test anyway for IFAB (as ordered by the prescribing nurse), I will try asking for the blood count etc stating the NICE guidelines. At the very least it would be interesting to compare how and if my blood has responded to the B12
I will report back with result if I manage to get the test agreed
Not all cases of B12 deficiency present with anaemia, despite the 'Pernicious Anaemia' name. However, even without anaemia, it is likely that there would be some abnormality in the blood count.
Good to hear that you feel you've improved since starting treatment. Comparing current with previous results is always the most sensitive way to approach things because the 'reference ranges' in use are so comparatively wide, as they describe a large whole population.
A positive IFAb would be an interesting finding, but a negative result doesn't exclude PA.
In the end I had my blood test last week. The nice nurse agreed to do a full blood count as requested and especially with my having mentioned the NICE guidelines about this.
After 3 injections of B12 and a 3 weeks of daily sublingual 2000ug I had hoped the blood result would have boosted a bit, but generally result much the same as before starting treatment and with WBC/neutrophils still in the lower range, though in range.
Unfortunately due to my distracting the nurse by asking for the FBC she forgot to order my IFAB. This was the original point of me having the blood taken. I will have to try for this test again
Leaving the IFAb a bit longer won't harm at all. Don't worry about the WBC & neutrophils, especially if they're in range. Some folks do just run lower numbers like that. I'm not suggesting you try, but if you ran round the block a few times and had your blood taken then your WBC would probably rise a bit.
Nurse will have taken the FBC sample into an EDTA anticoagulated tube. The IFAb is done from a clotted sample, as it's done on serum. You'll get there eventually.👍
It turned out I did have my IFAB test. It was negative. It took 6 days for result to come back whilst the Full Blood Count came back same day.
In case of interest to anyone, I was notified by this website of the results patientsknowbest.com/ I did not work out how I signed up to it, my GP surgery is not sure, but I think it looks good and helpful way to merge health data
Anyway, I have completed 5 loading doses. I still not know cause of my B12 deficiency but have been advised not to take any supplements and see if symptoms come back, and maybe have a B12 blood test in a month or so, then I can monitor it
It sounds like if you've got PA then it's IFAb-negative. As long as it's treated then it's largely irrelevant, as it's just another cause of B12 deficiency. [I know 'patientsknowbest' and it's a good system.] The FBC back on the same day is good, and the IFAb back inside a week is excellent. Labs process hundreds of FBCs per day, whereas the IFAb test is done in small numbers so it is probably batched to avoid reagent wastage. My guess is that it's done 'in house' because if it was a 'send away' test then it'd be likely to take a bit longer for the result to come back.
You say you don't know the cause of your B12 deficiency. If all the other likely causes have been eliminated then PA seems the likely answer.
Hi again Flipper, from your experience, do you know if GP practices/surgeries are charged for the blood tests they order? i.e. are they incentivised to do fewer blood tests?
I had initial FBC 10 days after starting B12 treatment as per the NICE and my CCG protocols. I returned 2 months later expecting to have another such blood test as per the protocols. However I was told it was not required since my last results were, they thought, fine. They did take my B12 levels and vit D which were about 800 (up from 156) and 60 (standard units) respectively.
I am very curious why they did not do the full tests which I asked for and as stated was required - they were already inflicting me with a needle prick so it was not for want of sparing the patient.
If I were in the doctors position I would rather over test than under test, it is no skin off their chest - but maybe such doctors would lose out financially? I do not understand their thinking
This is getting political rather than scientific, and I don't know the current situation! Everything that's done by labs has a cost, and when it's possible to save money that can be used elsewhere, that [in my book] is good, but only if it's saving an unneccessary test.
An extra full blood count in real terms only adds a very small amount of true cost, because we perform millions of them annually.
The other tests like B12 and Vitamin D cost considerably more to perform.
Testing for B12 when you're on treatment with B12 is the action of someone who clearly doesn't understand what's going on. It's not recommended, and the evidence is quite clear. If the needle goes in and delivers the B12, where else is it going to go?
If you had visible megaloblastic change [macrocytosis and a reduced haemoglobin] that [to me] would make more sense, to show that there is recovery. but that's a clinical decision... Leave me out of it! Good luck.
Politics is a reality so some times things may need to be seen through that light to understand what is going on. And some doctors seem very reluctant to authorise blood tests, so I was interested to know if their was some non-scientific explanation
I still do not understand why my doctor preferred not to follow the guidelines of the FBC at 2 months from start of treatment. I will email them my concerns. I never spoke with them directly, a nurse liaised with them.
And if they disagree with the protocol they should feedback to the authors so that the protocol could be updated with their improved process. Reminds of a letter in the Times recently from a retired doctor who said it should not need years to train a doctor, you just need people who can follow a process.
And about testing blood levels of B12 - is there any idea how long from last injection of B12, blood levels of B12 could be tested to show a meaningful amount? my thought was that excess B12 in the blood is fairly quickly absorbed into the liver or excreted with urine from the body
Links below are to forum threads where I left detailed replies with lots of B12 info which you may find useful eg causes and symptoms of B12 deficiency, B12 books, B12 websites, UK B12 guidelines, B12 articles and a few hints on dealing with unhelpful GPs.
Just for clarity - the test is being done in relation to whether B12 is resolving anaemia - but anaemia isn't present in at least 20% of patients that present with B12 deficiency.
Thanks for information. Sorry if this is a silly question - how is it known if anaemia is present?
One idea I had was that RBC can seem normal from the blood test, however the shape of the RBC mean they can not carry as much oxygen which results in a form of anaemia. However to know if this problem exists it would be necessary to look at the RBC under a microscope to see if they are enlarged?
To put some context about my case, I had two blood test down 6 months apart. All was fine except for the low b12 which stayed around 116 pmol/l or 160 ng/l for this period.
It can be difficult to interpret a full blood count as it is possible to have both macrocytic and microcytic anaemia going on at the same time. This is why a lot of measures are looked at.In macrocytosis red blood cells are both larger and rounder than normal which means that the ratio between volume and surface area is changed and this is what affects the ability to transport oxygen from the lungs - lower surface area from being rounder means that less oxygen can be transferred.
Thank you for details - and these words! Looking it up I see a "peripheral blood smear" would diagnose this better than only something in a test tube or centrifuge
"A procedure in which a sample of blood is viewed under a microscope to count different circulating blood cells (red blood cells, white blood cells, platelets, etc.) and see whether the cells look normal."
I imagine it is more expensive to do, so not done so often. I previously asked some private labs about looking at blood under a microscope and none did it. Now that I have the word for this assay, I may be better able to find it
In case of anyone reading this, I see now that the test is also known as "blood smear"
Whilst I am writing about private blood tests, I found and did mine via patient.info and through which I went to a local chemist in London who took my blood.
It was a very good service and cost £140 for testing most things including vit B12 & D plus all the normal things and some more. Not cheap but a much better price than I have seen in many places in England
And interestingly the chemist used the following lab for doing the actual testing. The lab operates within the M25 around London and also has its own shops for taking blood plus mobile units londonmedicallaboratory.co.uk
Anecdotally, since I started taking sublingual b12 (about 3 weeks ago) and now more recently B12 injections (last week), I have not, I feel had the extrema fatigue which used to hit me a few times a day over last year
Looking at my blood results again, whilst I did not have a blood smear done, my blood results do not suggest anaemia. My mean cell volume (MCV) was 90 to 85 femtolitres over 6 month period. I read it should be over 100 to suggest Megaloblastic anaemia
Is B12 deficiency thought to be the cause of extreme exhaustion through any mechanism other than anaemia?
And even if I had any anaemia, I would imagine anaemia would take more than a few weeks to correct, so the B12 supplements for me are presumably acting via another way
Of course, I am just one person, everyone is different, and it could also be coincidental etc!
B12 is also involved in the Krebbs cycle - the process your cells use to release energy so that is another way B12 could possibly affect energy levels - there are probably others.
Guidelines below suggest anyone with unexplained B12, folate or iron deficiency should be tested and patients with a first degree relative with coeliac.
Any chance of internal parasites eg fish tapeworm?
Have you eaten raw or uncooked fish in past?
Have you lived or stayed in an area where internal parasites are common?
There are other parasites besides fish tapeworm that can lead to B12 deficiency in humans.
Giardia Lamblia is one and there are other types of parasitic worms.
One potential sign of internal parasites is an increase in eosinophils, a type of white blood cell. Eosinophil result can be found on Full Blood Count results.
Some medicines/drugs have been associated with low B12 levels including metformin, a diabetes drug, PPI drugs and some anti epileptic drugs. There are others.
Any concerns about medicines/drugs should always be discussed with your doctor.
High alcohol intake can be associated with low B12 levels.
I'm assuming your GP has already discussed your diet with you.
If not, may be worth writing out a typical weekly diet, food and drink for GP.
Do you eat plenty of B12 rich food eg meat, fish, shellfish, eggs, dairy, foods fortified with B12?
If yes to a B12 rich diet then dietary B12 deficiency is less likely and it is more likely that there is an absorption issue in the gut.
B12 books I found useful
"What You Need to Know About Pernicious Anaemia and B12 Deficiency" by Martyn Hooper
Martyn Hooper is the chair of PAS (Pernicious Anaemia Society). Book does not show updated BNF treatment info. See BNF hydroxocobalamin link in my other reply for up to date info.
"Living with Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper
Has several case studies.
"Could it Be B12?: An Epidemic of Misdiagnoses" by Sally Pacholok and JJ. Stuart (US authors)
Very comprehensive with lots of case studies.
"Vitamin B12 deficiency in Clinical Practice" (subtitle "Doctor, you gave me my life back!" by Dr Joseph Alexander "Chandy" Kayyalackakom and Hugo Minney PhD
Don't rely on there being evidence of a past diagnosis of PA (Pernicious Anaemia) or other cause of B12 deficiency in current medical records.
If you get proof of diagnosis eg positive test result/letter from specialist confirming diagnosis etc keep a copy in a safe place in case needed in future.
Best piece of advice I ever got was to always get copies of all my blood test results.
I am aware of forum members who have been told everything is normal/no action on blood tests when there are actually abnormal and borderline results.
Emphasises need to treat patients who are symptomatic even if their B12 level is within range.
Low dose oral cyanocobalamin (50mcg) tablets are sometimes prescribed for dietary b12 deficiency in UK. My understanding of UK guidelines is that B12 deficiency with neuro symptoms present should be treated with B12 injections whatever the cause of the B12 deficiency even diet.
There are moves across UK to put more patients onto high dose oral cyanocobalamin (1000mcg) as an alternative to B12 injections. Although this is sometimes promoted as easier for patients, cynical me suspects a cost cutting measure. B12 ampoules for injections are relatively cheap (less than £2) but nurses' time to give injections isn't.
Article suggests that there is no proof that oral b12 is as good at treating B12 deficiency as B12 injections.
This next study from Madrid, Spain was quite positive about oral treatment but I'm not sure what was the cause of the patients' low B12 levels.
I'm not a scientist or health professional but I'm guessing that people with dietary B12 deficiency might respond differently to people with absorption issues.
I think a lot more research needs to be done especially on how effective high dose oral B12 is in treating B12 deficiency due to absorption issues such as PA.
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