high B12 levels


my recent annual blood tests have shown an above range reading for B12 -only slightly at 660 with lab range of 180 -630. I also have a high reading for the liver enzyme GGT at 71 ( 6 -42 ) which I have had up and down for a number of years. neither of these readings have caused the Gp to ask me in to discuss but as I have read high B12 can be associated with liver disease and because the current high levels of GGT obvioously point to some issue with liver function albeit of a number of years standing I am ordering some private tests with Blue horizon. However I have just seen that their active B12 ,which is what Ive ordered ,says the active B12 is only 10 -30 % of the levels in blood . Im therefore wondering whether this will be of any use as it may come back within range but could the non tested levels of B12 still be high ?

thanks for any light you can shed on this

6 Replies

Doctors usually do an ordinary b12 test and no more than 20% of that is the active, the part that is useful. So your result of 660, really is 528 which is actually just under your range. It is thought that b12 levels need to be about 1000 to prevent both cognitive and neurological impairment. You may want to check out the pernicious anemia society community who can answe your query more fully. I would say your level of 528 at the most is deficient, but it goes by your symptoms too. Please look at the PA forum and b12 websites for information.

I have b12 deficiency, hashimotos and high liver function levels which are all linked to the thyroid. Also you can have high levels of b12 in the blood but unless it's getting into the cells will be useless. Although your b12 level is low. I take b12 supplements daily and have injections weekly and feel much better.

surely the lab ranges take into account that percentage - if not then the numbers become meaningless as far as working out high and low levels ?

No they don't sadly. Look at the information on the British National Formulary and the British Committee on Standards in Haematology whose guidelines discuss how flawed the tests are. Your GP should have read all this, but the only way I got my injections eventually, was giving a copy of these documents plus others to him.

Sorry I don't have the links at hand, but if you repost this on the PA forum of health unlocked you will be given links.

Labs, as well as doctors, don't really understand the issue, plus labs differ throughout the country.

You might find this helpful :



thanks for that but everyone seems to focus on accurate testing for deficiency. my concerns are working out if there are any true indications of high levels ( in the absence of supplementation ) as this can be a result of liver disease / cancer and i already have high levels of a liver enzyme.

This link is going to scare you, I'm sure of it, but you did ask :


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