Hi all, read today on another platform that your symptoms when your b12 is low are the same as when your b12 is too high! To me this makes no sense at all, anyone with more b12 knowledge than me (wouldn't be hard) care to clear this up .
Many thanks .
No, this is not true - complete nonsense.
Try telling that to my gp, grrr😂
Ask your GP to point you to a scientific paper that refers you to that piece of nonsense . ( but don’t say piece of nonsense !)
You're right and it is utter nonsense!
Some people respond to high serum B12 levels in a way that seems to prevent the B12 transferring from blood to cells. This is known as functional B12 deficiency. It is common enough for functional B12 deficiency to be a recognised side effect of some conditions - such as liver and kidney problems - that can lead to raised or rising serum B12.
This is very different from saying that everyone who has raised serum B12 will have the same symptoms as someone who has low serum B12.
This is a link to an article on the possible causes of raised serum B12 and functional B12 deficiency arguing that it could be a useful early indicator for some conditions
That is true of iron but not B12.
The bit I have a problem with is the 'too' - it is possible to have symptoms of B12 deficiency with low serum B12, or mid-range, or high. But for most there is no such thing as too high for serum B12. As Gambit62 says, high unsupplemented serum B12 can be an indicator of other things going on, but can also be a sign of an inability to use the B12 cellularly, and you can have one without the other. Other Bs (possibly all, I don't know) can be similar. B9 may be high in range but cells be deficient, if the vitamer used is less accessible to the individual in question, or with some genetic variants. Unmetabolised folic acid can accrue. B6 can give similar symptoms with low or high serum, particularly in the case of pyridoxine supplementation, as pyridoxine blocks the function of the active form P5P - so blood looks high but still deficient and symptomatic.
There are many symptoms of B12 deficiency. We do not all have the same symptoms - or frequency and severity of those symptoms. This makes it hard for GPs to recognise it by symptoms alone. Plus, several symptoms appear under lists for other vitamin deficiencies too. Their teaching on this subject is flimsy, many symptoms commonly mentioned here do not appear on any lists that they access. For a far more comprehensive list, it would be worth looking at the Pernicious Anaemia Society website, or Tracey Witty's.
When having a loading dose of 6 injections within a short space of time (the initial UK treatment when B12 deficiency detected), patients often get acne-like spots that generally are to be found on the face, particularly hairline. This could be viewed as a B12 reaction, but this is the only reaction to B12 that I'm aware of. For some people, this is a bigger issue - but for most, worth putting up with and temporary.
Some people with B12 deficiency find that one brand of B12 is more effective for their set of symptoms than another, or that they find it difficult to tolerate a particular brand - but this is not a reaction to "too high" B12.
B12 is used at very high levels in hospital when flushing out poisons from a patient's system precisely because it is harmless at high levels.
Adult Inherited Metabolic Diseases consultants, where a genetic problem getting B12 to cells or tissues is discovered, will advise GPs to administer 2 injections a week. NICE guidelines advise GPs to treat those with B12 deficiency with neurological symptoms by giving every other day injections until no more improvements can be gained by doing so. This is the medical guidance of experts.
Many here have experienced, when treatment starts, a worsening of symptoms before improving. This is believed to be due to damaged nerves reawakening. It is not a reaction to "too high" B12. It is part of the healing process.
Some other conditions can cause B12 serum levels to elevate - but this also is not a reaction to "too high" B12 - more an indicator. Renal problems would be a consideration here.
I think that you can rest assured. If not, have a read of StichtingB12Tekort .
I don't know about B12, I'm a novice. But this certainly happens with Hypothyroidism. Symptoms of too little or too much hormone for me and many others are identical. Making it impossible to know which way to adjust. It's a pain.
So there is a hormonal precedent for this kind of thing. As someone said above, in the case of thyroid hormone, too much will switch on a conversion enzyme which is quite aggressive, designed to stop us becoming hyperthyroid. This enzyme converts the active hormone to something inert and expels it. If it can do that for thyroid I don't see why it might not do it for B12 too.
Just wanted to let you know this is something that happens in other situations.
I think you have been misinformed by the article. First, the B-12 levels in a blood test are estimated. How low the B-12 level is more familiar because there are a couple more tests done at the same time and those tests, along with the patient’s symptoms,alert the doctor that the possibility of having PA is more likely than not. They sometimes prescribe B-12 injections or advise you to take sublingual B-12 drops. If you have pernicious anemia, be prepared to take the whole bottle every week and you may or may not get the B-12 your body needs. The reason your body is not processing B-12 is because intrinsic factor required. Intrinsic factor is produced in the stomach . Without intrinsic factor, B-12 is not picked up and becomes low. Also, persons who have diseases that affect the small intestines or people over the age of 60 can have very little intrinsic factor because of medical conditions or age. An intrinsic factor blood test will normally be positive, negative, or maybe. Negative means no intrinsic factor has been found in the blood . Positive means intrinsic factor is found, but whether the intrinsic factor is a normal or reduced is the question. If the symptoms tell the doctor that the patient has PA and they are not elderly nor do they have a disease involving the digestive process, to further assist the doctor who needs reassurance, the next step is another blood test to see if the patient has anti-paretial cells. If so, the paretial cells are being destroyed and without them intrinsic factor is not produced. Blood test for intrinsic factor, and then, if necesssry , an anti-paretial cell blood test. I may not have spelled paretial correctly but hopefully close enough. 😊
As for the normal to high B-12 level, that doesn’t prove a thing. First the B-12 level normal or high is an unknown . Symptoms are supposed to be used to warrant the intrinsic test or anti-paretial cell. Most doctors should know the symptoms of PA and want to be certain their patient is not misdiagnosed. As for B-12 level being too high, B-12 excess goes to the kidneys where it is removed in the urine. B-12 at a high level can be high with non-functional or inactive B-1. The B-12 passed through the stomach but there was no intrinsic factor for it to activate it. A lot of time PA or B-12?deficient people keep taking the oral B-12 by tablets or sublingual and have the CBC without stopping the oral B-12 and their B-12 level will, of course, be really high. But, the intrinsic factor and/‘ or the anti-paretial blood tests with symptoms should settle the question of PA or deficiency of the intrinsic factor . I am just a PA patient who was diagnosed many, many years ago as having PA by the Schilling test. I did not get a copy of the Schilling test to prove my PA to doctors I was seeing about 4 years ago. They didn’t believe me, of course. I became very fatigued and my inherited neuropathy progressed rapidly . I saw an Endroconoligist who ran the intrinsic and anti-paretial test and it was negative for intrinsic and positive for anti-paretial cells. I inject my B-12 myself . Being elderly has nothing to do with intelligence nor ability. Medical conditions determine the extent of both intelligence and ability, Sure wish the majority of doctors weren’t so busy practicing ageism that they are blind to their patients’ needs. I could have misspelled the word “paretial,” but I’m too lazy to look it up and my iPhone doesn’t know medical terminology. Please keep informed on all aspects of B-12 and keep any tests you may have in a safe until you die.
1000 percent agree with your ageism!!!!!
Ageism is a serious problem in professional health care. Getting the medical care that you need becomes unbelievably difficult. About 4 years ago, PC I had been seeing for no less than 8 years decided , from one CBC B-12 level, that my level was high so I must not need my B-12. I have always injected my own B-12 but she didn’t give me the RX to get it. I researched a lot and realized why the level can be high on a blood test , especially if you have just had an injection. I got more weak and fatigued and the peripheral neuropathy triggered an episode . After 6 months, I went to the Endroconoligist to rule out thyroid etc. I knew by the Schilling test I had PA. Took the results to a new PC. Haven’t stopped since. That was only the beginning! I never liked going to see a doctor but sometimes you have no choice . I have dealt with such blatant ageism now though that I am determined not to go near a hospital. I never realized the how they feel about senior citizens . In my age group, we didn’t have the hardship our parents had and have an easier life . Now, in many countries, there is at least a 10 year difference in our medical condition, even with medical problems because we can get treatment. Our physical ability at ,60, 70, even 80, is much different than the generation.before us, by no less than ! 10 years. Fighting for your right to continue a B-22 treatment when you reach a certain age group is demeaning , frustrating, and totally unreasonable. It isn’t just B-12 and I am far from being alone.
Updated B12 and folate results
Topping Up B12 Supplements. 
B12 
B12 deficiency and b12 deficiency anemia
