Blood test results show my vitamin B12 level is 2000

I'm a Senior female who recently had a blood test that shows a high level of vitamin B-12. The level is 2000. I have never taken the B-12 shots only multi vitamins. I have diabetes and have read that a high level of B-12 could be linked to diabetic kidney cancer. What test do I need to ask for to see if this is a possibility?

23 Replies

  • I'd recommend that you actually speak to your GP about the result and what investigations are appropriate.

    Although it has been suggested that high B12 levels could be used as an early indicator for some conditions affecting the liver and kidneys it isn't formally recognised as a diagnostic tool in this area and there are other potential reasons for the elevated levels of B12. Your GP will probably need to refer you to a specialist for further testing.

    Possible that you might get more support posting on other forums that are more directly related to cancer. This is one of the dozen or so that comes up if you go to the search communities (under the 'my communities' menu on the top bar) and put in kidney cancer

    you may get a more precise response in relation to diagnosing a kidney problem there.

  • This mqay be a little off topic so I apologise. Is thickening of the ileo caecal valve in the bowel a complication of taking for example Vit B12 and or ferrous sulphate? Many thanks

  • honest answer is that i have absolutely no idea - had never actually heard about the ileocaecal valve before your query - not a medic and tend to look things up and learn about them as needs arise but it is quite a fascinating topic - and could explain why we get some people reporting swelling in legs as that would fit with the valve not closing properly.

    The valve is actually a muscle so I'm not sure that either B12 or ferrous sulphate would directly cause a thickening ... and I didn't have time to do enough research to fully go in to what might cause problems with the valve opening and closing.

  • This could also be functional B12 deficiency where one of the transporters doesn't carry the B12 from the blood across into the tissues, so it gets stuck in the blood. The blood level will show as normal or high. Do you have any symptoms particularly neurological ones ?

  • I may be wrong but I think that Cher-2000's concern is about what is causing the high levels of B12 as she hasn't supplemented and it is very unusual for levels to be that high without supplementation.

  • Hi Lilnicki, this was my situation. My serum B12 was over 2000 (unreadable I was told) however I actually had pernicious anaemia due to the fact b12 did not reach the mitochondria and was being 'stored in the blood'. I had loads of symptoms including neurological - great answer!

  • How do you get tested for PA?

  • I was not actually given a 'test' as such because the way the NHS evaluated pernicious anaemia back then (when I was diagnosed) was basically useless (as per my doctor at the time).

    Since then the NHS have given up doing that blood test to determine B12. Other indicators such a Methylmalonic Acid test and Homocysteine Test which could prove useful in our circumstances are unfortunately not given by the NHS.

    My diagnosis was made on symptoms and clinical findings by my haematologist and gastroenterologist. Due to what was found, it was agreed that I could be treated on an empirical basis by the NHS for the deficiency of B12.

    There are many different avenues within the body that can go wrong prior to getting B12 into the mitochondria and it seems to me that, because of this, many doctors these days like to refer to the condition as 'B12 deficiency' rather than 'pernicious anaemia'. I have had both terms used by the medical profession about me.

    However, in my opinion at the end of the day, I believe that any symptoms that are caused by a deficiency in B12 within the body needs to be treated with a cobalamin of your own choosing. By that I mean whatever works best within your body should be used, however our NHS only gives Hydroxocobalamin which is great if it suits you but is useless if it doesn't.

  • Functional deficiency can be a cause of high B12, but yes all causes should be looked at. It's good to have information from different people on their own experiences as one of them may be relevant to her.

  • it isn't clear from Cher-2000 post whether or not she actually has any B12 symptoms and it is quite likely that she may not, though you are right that she could.

  • Hi... What symptoms do I need to know?

  • symptoms of functional B12 deficiency will be the same as those of B12 deficiency


    there is quite a lot of overlap with diabetes eg diabetic neuropathy so may be difficult to unravel what is going on

  • I am interested in this concept of functional deficiency.

    I have Hashimoto's (hypothyroid) - eventually after long sorry tale of inadequate treatment on NHS, I did (as many others on thyroid Uk do) get a full thyroid plus eleven test from Blue Horizon, about two years ago

    This showed very high above range B12 & top of range folate. I had never supplemented either. (Most with Hashimoto's have low B12 - so I was very surprised)

    But same test revealed I had very low vit D, low magnesium also revealed once I tried supplementing vit D.

    Started gluten free diet, & I was able to stop propranolol - been stuck in that over 17 years (propranolol lowers magnesium)

    A high percentage of Hashimoto's patients are gluten intolerant

    On vitamin D & magnesium, my B12 & folate started falling.

    Cutting long story short. About a month after started supplementing vitamin D this caused/revealed low B5. (Peripheral neuropathy) so started taking vitamin B complex .......soon after revealed low B12 (severe pins & needles)

    Now improving on B12

  • Gambit62 is correct - you need to see a doctor about this. There are many possible causes of elevated B12 - various cancers, liver disease, autoimmune problems, malaria, diabetic renal disease - - some of them scarier than others. Differential diagnosis isn't likely to be a single test.

  • Here's another paper that talks about a functional deficiency being possible with very high B12 levels. The high levels can be caused by an excess of haptocorrin (the protein that binds B12 in an inactive state).

    It includes a flow chart for various tests to distinguish possible causes.

  • Thanks so much for the information. What I didn't mention is that I have two MTHFR genes...the famous ones which as you know can cause a methylation problem, poor absorption of nutrients and vitamins and minerals. I've read that I need to get a Active B-12 test to determine how much B-12 I am absorbing into my cells. I will be calling my Dr. tomorrow to ask for the test. Then I'll go from there. Thanks for being there and giving me feedback to try to figure out what's going on inside my body.

  • The active B12 test is unlikely to help unless you're trying to figure out why you have symptoms of a B12 deficiency despite such high serum levels. If you are trying for that then an MMA test is more likely to prove useful (although both are highly likely to give normal results).

    The MTHFR mutations, unless they're both the C667>T mutation (i.e., you are homozygous) are very unlikely to have any effect. Some people who are homozygous (a very small proportion of the population) will benefit from taking methylfolate instead of folic acid. The mutations will have zero effect on the absorption of vitamins and minerals.

  • My Mother in law had pernicious anemia and vitamin b-12 shot for seven days straight then once a month fixed her right up. Felt brand new. Good Luck . Only suggesting no dr here.

  • My serum B12 was over 2000 (unreadable I was told) however I actually had pernicious anaemia due to the fact b12 did not reach the mitochondria and was being 'stored in the blood'. I had loads of symptoms including neurological.

    You will be lucky to get a holotranscobalamin test on NHS, I know I couldn't, but I hope you do. I have two of the MTHFR mutations (heterozygous for both) and I know I certainly respond incredibly well to folate rather that folic acid, but I also need methylcobalamin rather that hydroxo as I can't convert.

    The methylation pathway is a complicated system and it takes an awful amount of research to reap rewards, however if you dig deeply enough you can do it.

    Good luck!

  • but I also need methylcobalamin rather that hydroxo as I can't convert.

    That's not very likely. With only one copy of the C677>T mutation your methylation efficiency should be around 80% of normal. And supplementing with methylfolate would fill the gap in the synthetic pathway to methylcobalamin.

  • Read above reply about pernicious anemia and b-12 shots. Good luck.

  • The only reason I made reference to the MTHFR polymorphisms was because they had already been mentioned. I have numerous homozygous single nucleotide polymorphisms some of which lay directly in portions of the pathway which had a direct influence on (but not restricted to) the health issues being discussed here. I had to deal with each one in turn. I didn't mention the others as I don't think it would be relevant and also make for pretty boring reading.

    These SNPs don't work unilaterally unfortunately which is why it is practically impossible to advise someone about this without knowing all their SNPs from their complete genome. I always advise the assistance of a qualified health professional. Unfortunately our NHS is not quite there at present so it would probably have to be private.

    There are a number of pieces of literature and health professionals who will agree with what I have said. Indeed there is a pernicious anaemia society meeting in Birmingham this December, the members of whom are very interested in why people like me can't convert things like hydroxocobalamin and thyroxine etc.

    So I am sorry but I am living proof of someone who cant convert certain medications. It took me 16 years to research my health and although it was a hard slog it was incredibly fruitful in the end.

    Everyone here has me very best wishes in finding the answers they need to their medical issues.

  • please see my posts - my B12 id 6000 and active B12 660, normal MMA , normal homocysteine.

    Symptons of low B12

You may also like...