All right, our last question of the day. Ekatarina
says, "There is one more question, if you have time.
Why MCV..." Which is mean corpuscular volume. Which you would see on a complete blood count
or CBC. "... Why would MCV be elevated despite supplementation with B12 and folate? Organic acid
levels of FIGLU and MMA are in the range." FIGLU is formiminoglutamate, which is an
inverse marker of folate status with emphasis on unmethylated folate and methylmalonic acid or MMA,
not to be confused with mixed martial arts, is an inverse marker of vitamin B12 status.
So, what MCV is telling you is that your red blood cells are bigger than normal
and so first of all I would look at how elevated is because
if it's two points above the top of the reference range and it's flagged as high,
but barely flagged as high, then you might want to just retest it and see if it stays high. But you
also might want to see if increasing your folate status or your B12 status, but especially folate,
you might want to see if that helps because it's entirely possible that... So, first of all,
FIGLU is very specific to tetrahydrofolate or THF, which is the unmethylated and unmethylenated, and
unformylated form.... It's the most basic form of folate.
Whereas methylation is going to depend on methylfolate and
your MCV is going to depend on methylene tetrahydrofolate. So it's possible
that if you have a polymorphism in dihydrofolate reductase that's lowering its activity,
that you might have a hard time supplying the methylene folate needed to keep the MCV down
and you might be dependent on a higher amount of folate to do that. And you also might
get a better response from non-methyl forms of folate such as folinic acid.
And then it's just always possible that 400 micrograms of methylfolate
doesn't minimize your MCV, but 800 micrograms does and the 400 was enough to keep the FIGlu in range,
but it wasn't enough to keep the MCV and range, that's also possible. With that said,
if folate and B12 are not part of the answer the next thing I would look at is copper.
And so I'd measure your serum copper and ceruloplasmin because copper deficiency can cause
a wide diversity of blood cell-related issues where usually the neutrophils being low is the top
thing you would see. But sometimes it's an anemia that looks just like iron deficiency anemia.
Sometimes it's an anemia that looks just like B12 and folate deficiency anemia.
Sometimes it's isolated, low platelets. Sometimes it's broadly low white blood cells.
So, go through the steps of folate. See if increasing the dose or using folinic acid instead
of methylfolate, if that's what you're using, does the trick. If that doesn't do the trick,
then I would look at copper next. And then if copper doesn't do the trick, then
you go back to the drawing board. But I would start there. All right, thank you Ekatarina.