In MTHFR Update 1 I mentioned that my doc decided to test me for MTHFR variants.  She figured if I had it, then it would help convince my child’s doctor to test him for it. 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 has helped a lot with fatigue. This also explains why for years my serum CBC has shown B12 anemia that was not responsive to B complex supplements. I was taking the wrong form. No one ever mentioned the form was important.

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)

Now I need to investigate my kids MTHFR status. I suspect he has at least one copy 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 found it is likely due to an inability to convert folic acid.  (

My doc recommended I start methylfolate but it caused side effects so I had to stop it until I could learn more. Turns out the dose was way too high. (1,000mcg of methylfolate, yikes)

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. We then moved to 5mg and are working with a doctor on testing.