High folate in the presence of low B12 is called the folate trap.
It is kind of complex...
The MCV in the CBC will be elevated or very very high and almost out of range when B12 is low.
People with neuro signs severe enough for a wheelchair or lost vision, may not recover 100% when B12 is fixed and returns to a more normal level. This damage would be at the spinal cord level, and be demyelinating.
But most people do get better, but it may be slow going.
http://www.ncbi.nlm.nih.gov/pubmed/6115113
If you type methyl folate trap into Google and look at images there are many graphs that may help understand.
You can see why doctors don't really understand all this. It is really difficult, and I only have a minor understanding of it too.
The testing to run would be the methylation DNA testing for MTHFR.
More at MTHFR.net
__________________
All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
************************************
.
Weezie looking at petunias 8.25.2017
****************************
These forums are for mutual support and information sharing only. The forums are not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider. Always consult your doctor before trying anything you read here.