Is doctor's remark accurate?

[zheshi14]

I'm in the beginning stages of possibly getting diagnosed, and asked my doctor about the specific testing and got this response:

"MTHFR is part of a cascade related to formation of homocystine. We will only see issues with this if your B12 level is low, not high. We know that your body is absorbing vitamin B-12 because we are detecting it in your serum. It is a vitamin that is absorbed through the gut with the assistance of intrinsic factor. If you are having issues with this your vitamin B12 levels would not be elevated. Please stop your B12 supplement. We will be rechecking your vitamin B12 levels again to assess a new baseline level. However this may be elevated due to your supplementation for several months to potentially even years. Again, I am not concerned about your B12 elevation itself, but we will be looking more into your liver function again."

Is this accurate?

[Gambit62 Administrator]

the bit about MTHFR seems pretty irrelevant (though it is true that MTHFR is the process that leads to high homocysteine if it doesn't run properly). Whilst B12 is involved in the process it doesn't seem to have a very significant impact on the efficiency of the process unless B12 levels are low.

The bit about the relationship between supplementing and high B12 and it taking several months if not longer after raising serum B12 with supplementation before you can get a meaningful baseline is correct.

[zheshi14 in reply to Gambit62]

So it's possible to have a B12 absorption problems and have high levels of B12 serum?

[Gambit62 Administrator in reply to zheshi14]

if you have had an injection then your levels will be off the scale after the injection and then fall over time.

If your levels were raised by supplementation with oral B12 in very high doses over a very long period of time then that would raise B12 levels though a significant rise is more likely to indicate that you don't have a B12 absorption problem.

If your levels are raised then they may take a log time to fall, regardless of whether you have a B12 absorption problem

[deniseinmilden in reply to zheshi14]

Yes, because if you take enough supplements some will get through - if only through the membranes of your mouth.

Some people have a problem with the individual cells in their body not taking up the B12 from the blood serum and in those cases the blood will test very high because any that does go in is not being used and therefore not being taken out as it should be so the levels gradually increase. These people will also show B12 deficiency symptoms because although it's washing around their blood stream, it isn't getting to where it is needed - into the cells.

I think this is the simple principle behind "functional B12 deficiency".

Because the cells aren't readily taking it out it can mean that it takes ages for the serum B12 levels to drop, by which time the person is half dead or more so and lots of damage has been done, some irreversible. This is why, once treatment has been started, it should be matched to symptoms and blood testing is irrelevant (British Society for Haematology guidelines).

The only way to get around this is to inject very frequently so that there is so much in your blood some gets into the cells for their use "without them trying to absorb it", as it were.

If you read through Gambit62's other excellent replies (you can go to her profile by double clicking on her name and looking under the heading "replies") there is more accurate and detailed information on this. You may have to go back a long way to get all the information but I'm sure it is worth it.

[zheshi14 in reply to deniseinmilden]

Thanks for the reply!

If you had to guess, what % of people that have PA/functional deficiency do you think initially tested high?

[flosslechops in reply to zheshi14]

last year i had a serum b12 reading of 404 (190-910ng/L) and a folate reading of3,4 (3,90-26,80ug/mL) so i took a 6000mcg b12,a 1000mcg folate a day and ate liver and onions 3 times a week for three months.the next blood test revealed b12 was 452 ng/L and folate was11,1 ng/mL and the first reading was without supplementing so i would say yes