OK so I've been injecting for some 6 months now (my doctors know) as functional B12 deficiency is suspected due to my PA. At first I injected 3 times a week and after 4 months my macrocytic anemia regressed as did my lymphocytopenia and thrombocytopenia. I was at about 11000 for B12. Since then I reduced the injections to see if I can get by with less and the symptoms crept back. I noticed I was excessively tired last week then out of breath. At the end of the week I had a blood test and my B12 had gone down to 6000, macrocytic anemia back, low lymphocytes, low platelets. This time they tested folates (I don't supplement and my diet, as it is restricted, isn't folates rich) and it came back at 769! I found mention of a 2006 study in which a doctor discovered that PA patients can have very high folates levels as the disease disturbs the pathways used to absorb folates, so high levels in the blood but not at a cellular level. Unfortunately the paper didn't mention what can be done. I'm back to injecting every day for the moment and I see my gastroenterologist in a month. In the meantime has anyone here had this problem?
Folates sky high: OK so I've been... - Pernicious Anaemi...
Folates sky high
It is correct that low levels of B12 can cause very high levels of folate - with all of the symptoms of a folate deficiency. This paradox is known as the 'folate trap'.
There are several different types of folate, all of which are important (especially for the making of, and functioning of, DNA). One type is methylfolate (aka 5-methyltetrahydrofolate.) All of these folates are interconverted in a nice cycle - frankhollis.com/temp/B12%20...
B12 is involved in one of those conversions, whereby cob(I)alamin (from B12) and methylfolate are used to convert homocysteine to methionine. In the process the methylfolate is converted to tetrahydrofolate - and goes back round the cycle.
If there isn't enough B12 then this conversion cannot happen. Homocysteine builds up - and so does methylfolate. And, because the methylfolate cannot get converted to the other forms. all of the folate in the body slowly gets turned into methylfolate. The body is full of this form (that it cannot actually use) and none of the others.
You obviously don't have low levels of B12. At least, not in the blood. You need to know what's happening in the cell.
As I said, methylfolate is used up in the conversion of homocysteine to methionine. If that conversion doesn't happen - for whatever reason - then methylfolate and homocysteine will increase.
Have you had your homocysteine levels measured? If they are high then you'll be closer to knowing what is happening. However, the answer won't be simple. It could be a problem with the enzyme that does the conversion - methionine synthase, or with the proteins that transport cob(II)alamin, or the enzyme that converts cob(II)alamin to cob(I)alamin,or something I haven't thought of.
But for now - I would increase the B12 frequency.
Whatever the problem it's not likely to be a complete failure of the process, but a reduction in efficiency. It may be that extremely high levels of B12 can get enough cob(I)alamin to where it needs to be to do enough to keep things at bay.
Good luck.
Thank you very much for the concise reply. I was offered both an MMA test and homocystein a few months ago but after the loading doses began. The MMA test came back normal and I suspected the homocysteine would too so I didn't get it done. I can still have it done, if it comes back normal does that mean it could still be a folate problem due to any of the other reasons you cited? I'm afraid another negative test will have me down as a hypochondriac.
Can't imagine how you could be seen as hypochondriac by anyone when, with B12 down to 6000- whatever the unit of measurement used, that's still very high- you are found to be macrocytic again. Add to that a very high folate level, there is obviously something there that needs investigating further. Not because you are asking, but because the medical evidence is there.
Don't give up, expatkerry , and don't let them give up either.
Thanks, I won't. I have an app with my GP in a couple of hours.
Good. You are trying hard to find answers and improve your own health- hope GP appreciates how hard it is to follow this type of science especially when lacking the physical, mental and emotional energy we once took for granted. My best wishes go with you to that appointment.
Update after Dr appt: I managed to get an appointment with a haematologist who may (or may not) throw some light on this, what a pity I had to insist. I also went and had the homocysteine test done, results in a week. The irony is after 6 days of daily injections the breathlessness is almost non existent today.
...which completely makes your case, and is proving what Talbot and Turner rather briefly and vaguely described in their research as treatment for functional B12 deficiency. That you need a lot.
Why ? I think it was Foggyme who made an analogy with a dam wall: B12 level must stay really high for a trickle to get over the top to the other side and any minor depletion will not allow B12 to get over the wall...…..
except that she said it so much better !
Whether the dam wall is of our own making (overreaction of immune system ?) and whether it can safely be demolished in order that a "normal" amount of B12 would suffice- that appears to be the research required next. This would first require that someone, aside from Talbot or Turner, believe that this is a condition worth researching !
Don't hold your breath, expatkerry - especially not at the moment !!
Good luck with haematologists.
[My MMA was always raised - between 350-400 nmol/L with a range of 0-280 nmol/L , but homocysteine level was 7.2 umol/L in 2017 which is "normal"- no indication of range given]
B12 deficiency with High Serum B12?
GP saying no more jabs as result high
New to all of this Pernicious Anemia Confused about physical response?
Extremely low Folates but B12 through the roof. 
