hi all
my recent total b12 test came in at 468 (range 179-2000) so just 17% through range. I take sublingual b12 drops daily, a vitamin b complex tablet and I had a b12 shot a few weeks ago and so wasn’t expecting it to drop.
I got my active b12 test back today and it says 116 (range 37.5-150) so nearly 70% of range. Does that mean what little b12 I have 70% is available for use or is that ok?
sorry if it’s a daft question, I’m just learning about b12.
Thanks in advance
I've never had an 'active ' b12 test.I understand the serum test just counts all b12 in your blood.
You can't use all of it.
I woujd think you can in theory use all of the 'active ' measured.
Once on injections you don't need to keep testing levels ax long as the injections continue.
Go by symptoms.
It takes many months to clear / drop.
However most seem to need very high levels to get relief from symptoms.
I'm sure a scientific answer will come for you to explain this .
thank you. The active b12 was measured as part of my thyroid panel, my nhs one was just total.
The injection I had was one I paid for myself and I haven’t had one since though it doesn’t seem to have made much impact. Infact my levels have dropped in the last 3 months despite all my supplementing.
Sounds like an absorbtion problem then.
I've never heard of a B12 serum range where the normal range went all the way up to 2,000. AFAIK typically, values over 800-900 usually reflect supplementation or injections so I'm not convinced of the value of viewing 468 as 17% through the range. There is no B12 serum testing lab in Europe or US that would regard 468 as below range or or even low-normal. In Japan, under 500 is regarded worthy of treatment but I dont know enough about how their serum test compares to say what that really means. The active B12 likewise looks totally normal. But values after supplementation/injection really cant be relied on to assess adequacy of treatment
There is no gold standard test for B12 deficiency. Not even if you also measure MMA and Homocysteine. A functional deficiency may still occur, so you really so need to mostly go off symptoms, and that is very difficult as B12 deficiency looks a lot like many other illnesses such as MS etc.
thank you for that. I definitely have symptoms but as you say they are the symptoms of many things 🤷🏼♀️ I’m sure the doctor will dismiss it anyway. I’ll just keep supplementing and see if symptoms improve. Thanks again 🙏🏽
I would like to add just a tangential bit to Technoid's typically excellent response. B12 deficiency is a clinical diagnosis, based on what you tell the doctor, and what the doctor can find out by examining you, for example, by examining the level of sensation on the soles of your feet, examining your ability to balance, and so forth. Lab test results might or might not be helpful, but the diagnosis isn't driven by lab test results. When symptoms indicate B12 deficiency, but the doctor feels there is not sufficient evidence for diagnosis, the doctor should get as thorough listing as possible of symptoms and levels of impairment of the symptoms. Then the doctor should start a three-month trial of B12 injections, every other day or twice a week being best because there is no reason for less frequency, and at the end of three months repeat the assessment of symptoms and severity: if symptoms show improvement, that confirms the diagnosis.This process is described in an excellent article, written by physician/researchers for the purpose of informing physicians about the symptoms, diagnosis, and treatment of B12 deficiency with neurological symptoms, published in a peer-reviewed medical journal. The article is "The Many Faces of Cobalamin (Vitamin B12) Deficiency", published in the Mayo Clinic Proceedings (US). As a B12 deficiency patient myself (not medically trained), I feel the best thing a B12 deficiency patient can do to improve treatment received is to provide the patient's physician with a printed copy of this article. The article is freely available, in its entirety, on the internet.
ncbi.nlm.nih.gov/pmc/articl...
(Click "PDF" in the upper left corner to get the format best for printing.)
thank you so much! 🙏🏽
The upper level of the range in Sussex is 711 ng/L in a range of 197 to 711. Where do you live?
What's the lowest level of B12 that you have had before you started supplements? How much oral supplement do you take?
What are the main symptoms you are dealing with? It sounds from your user name that you are Knackered and that fatigue is your main symptom. You also mention thyroid tests and thyroid disease is also associated with fatigue.
hi, I had my test done by the lab at Royal Devon & Exeter NHS Trust? I don’t think I’ve seen this range before either. My last test before supplementation was at 505 but the range at that time went upto 771 so it seemed a lot better. Then I found out I had hashimotos thyroiditis (which I’m treated for) and b12 supplements are advised so I started with the b12 drops and bcomplex tablets. My symptoms are definitely associated mainly with hypothyroidism but lately I’ve noticed increased brain fog, pins and needles in my hands and feet, mouth ulcers and my main issue is that since august I’ve developed chronic pain in my right hip that seems to have no cause. I had read that this could be associated with the nerve pain of lower b12 so I’m just exploring really as I’d never looked at b12 as more than just a vitamin before.
How much oral B12 are taking?
The symptoms of brain fog, pins and needles you mention are often raised by people with PA. It might be worth asking for an Intrinsic Factor Anti Bodies (IFAB) test to see whether you have PA - it's routinely done along with B12 and Folate. It can give false negatives but apparently not false positives.
Your hip pain could be any number of things (e.g. bursitis, osteoarthritis, rheumatoid arthritis). Do you know your Vit D levels? There are diseases of the hip like transient regional migratory osteoporosis (TO) which are linked with low levels of Vit D deficiency. The modern name for TO is bone marrow oedema (swelling) syndrome; the symptoms are chronic pain (similar to a ligament injury) but it takes ages for the body to recover. Unfortunately it can only be diagnosed via an MRI - an XRay will not show the swelling. If your Vit D levels are under 50, it would be worth supplementing though you would want regular checks because you can overdose with Vit D.
Thanks for replying. I take sub lingual drops at 3000mcg and a vitamin tablet with 5000mcg plus I had one vit b12 shot a few weeks ago. Bursitis, RA and osteoarthritis have all already been ruled out. I do have mild hip dysplasia in both hips of equal measure but there’s no valid reason for the pain in the right one. I have been referred to orthopaedics so I should know more when that comes through. My vit D is good at 138 (range upto 200).
if you're taking 3 mg of B12 a day, then a result of 468 does not seem that high. If you had the B12 shot shortly before the test, that's going to distort the result significantly.
The Cochrane review of oral B12 treatment says that the data on oral B12 treatment is very weak. There isn't much consensus or guidance on oral treatment. The standard B12 tablet from Boots is only 40mcg. When I discovered I had low B12, I took 100mcg for a year which did not make much difference but then increased it by 10x to 1mg a day which did make a difference.
I wish that I had a B12 result from 20 or 30 years ago so that I know what constituted normal when I was young and healthy!
oh to be young and healthy again!
My b12 shot was 9 weeks prior to the test so probably not too much of an impact? My main worry is whether it’s PA so I know whether I need to manage it better. I have requested the instrinsic factor and MMA test but probably won’t get it and possibly not of much value if it gives false negatives. If I could get to the bottom of my hip pain it would be literally life changing as I’m struggling with mobility badly when I’m actually motivated to move. I think it’s a waiting game to see how things develop. I’m just far too impatient and once I get a new piece of information I run with it. Thank you for all your help 🙏🏽
I was also taking around 160 mcg for a while and it wasn't doing much, despite increasing level to 707 ng/L in my case. Once I started taking 5000 mcg, I noticed rapid improvement in symptoms.
Thank you for that - please can I ask which supplement you use?
Solgar methylcobalamin (sublingual) 5000 mcg
Scientist, not medic.
The upper bound of the serum B12 test is rather high. Your result for serum B12 sounds quite healthy to me. Bear in mind, we're all individuals and we're all different. These 'reference ranges' or [even worse] 'normal ranges' are derived from measured B12 results, ranked from low to high, and 'normal range' is taken as 'middle 95% of the results measured'. To make matters worse, these ranges are specific to the method used to measure the results. If for instance you went to another laboratory away from your usual local home one, it might use a different manufacturer, and the measured results might well be different.
If we were talking about measuring Haemoglobin, or Sodium, there's much less of this effect, but as we move away from these very common analyses, there is more bias between methods. If you stick to one lab and one method, you can avoid this.
There's no reason to believe that 'Active' versus 'Total' results in a better indicator. If 'active' was 'better' then we'd see the NHS labs moving away from 'total' to 'active' but I don't think that's happened yet.
I have no doubt I'll have insulted someone's service and beliefs, but that's not something that will keep me awake at night.
I could drone on and on for hours about this, with a wide range of examples, but I've said enough already!
I've had weird conversations about reference ranges with clinicians. When I ask what statistical measure (mean, mode or median) is used to calculate the range, there's no convincing reply but there remains an insistence that if your result is within the range it's normal. My levels have been as low as 201 ng/L and the best compromise interpretation that I've managed to agree on is low but normal!
With Vit D the reference ranges are even more complicated than those with B12 and they tend to vary considerably. The upper limit with Vit D (100) appears to be agreed because too much Vit D is toxic but the lower limits are not. There used to be 3 Vit D ranges 0 - 25 was deficiency, 25 - 50 was insufficiency and 50 - 100 was normal. It appears that recently the concept of insufficiency was dropped and the normal range is now 50 - 100.
The concept of insufficiency seems to be one that is worth keeping because it should prompt further investigation. If you're a troglodyte, then insufficient levels of Vit D would make sense, but otherwise an investigation into malabsorption and an evaluation of symptoms (often gut related) is worth doing.
The concept of insufficiency in B12 reference ranges might be useful. If you're not a vegan and your levels are insufficient, then a further investigation of symptoms is worth investigating - fatigue seems the most common symptom but gut symptoms are just as tell tale. For people with PA, low stomach acid will be a key indicator but hard to access as the serum gastrin test is not available in primary care . Low B12 can be associated with other gut condition like bile acid malabsorption; this is just as hard to diagnose as the blood tests and radio labelled test used to diagnose this are not available in primary care; elevated triglycerides and low B12 are the only tests that hint at bam.
My general advice to folks is 'Have you had it done before? Has it changed?' because there's little doubt that you know considerably more about the subject!
thank you. I have had it done before I started supplements and it was at 505 in range upto 771 so not bad at all. I’ve come across it whilst trying to sort out reasons for ongoing fatigue and hip problems plus other minor new symptoms. Since I started supplementing (when I found out I had hashimotos) it just seems to keep declining despite my best efforts to increase it 🤷🏼♀️
thank you for the info 🙏🏽
thank you for that, that makes sense. I’m probably just at the stage where I’m grasping at straws. I think it was just that since I added all my supplements my levels are declining and I’m struggling to work out what’s going on. Thank you 🙏🏽
Result of 'active B12 test'
B12 serum versus B12 active 
Is one type of b12 better than another?
Active B12 results & pregnancy 
IFA negative, Low Active B12 - advice please. 
