MTHFR is the buzz online lately and it’s far more common than anyone first though. It’s a genetic variant called methylenetetrahydrofolate reductase or “MTHFR”  for short. While up to 70% of the population has this normal variant it seems to be problematic in some ways.

Some have felt this was the cause for autism but more recent research seems to imply it’s not the cause but it plays a role.   A lot of ASD kids improve on methylation supplements. I never really thought we had MTHFR honestly.

My doc decided to test me for this because I am sensitive to a lot of things and I have a kid on the spectrum. I didn’t expect much really but I got my results back and I am heterozygous (one copy) for C677T.

I started methylcobalmin and it helped with fatigue. This also explains why for years my serum CBC has shown B12 anemia that was not responsive to B complex supplements.

Metabolism of folic acid. The role of Vitamin ...
Metabolism of folic acid. The role of Vitamin B 12 is seen at bottom-left. (Photo credit: Wikipedia)

The reason I’m talking about this is because I need to investigate my kids MTHFR status. I suspect so because of his abnormally high serum B12 in light of never having taken B12.

  • Age 8: serum B12 of 929 in a range of 211-911 pg/ml.
  • Age 9: serum B12 of 1293 in a range of 211-911 pg/ml.

His doctor didn’t really know why his levels were so high.  My research implicated an inability to convert folic acid could be the issue.  (

It was recommending I start methylfolate but it caused side effects so I stopped. The dose was too high.

Methylfolate Side Effects

  • shakiness
  • irritability
  • headache
  • anxious
  • fatigue
  • short of breath

I took some niacinamide after this one dose but it took me 2 days to feel ok again.

At this point I suspect my son may have MTHFR. He has fatigue, low energy and low stamina so we began him on 500mcg of MB12 and worked up 1mg. His response to MB12 has been great. Later we raised to 5mg.