@SDSue
My B12 levels were always on the upper end of normal.
I choose to view this as the B12 could not get into the cells where it was needed. In 2011, blood work indicated an above normal homocysteine. The Dr started to tell me that I needed to take B12 and folic acid but fell silent when he saw that I had been on these supplements for years.
This was the opportunity to understand that something was wrong with methylation and that likely folic acid was the wrong approach...as was cyanocobalamin. Instead, the Dr's answer was to change the topic. Had he known more, I might have been saved from this path.
I have not given TCN2 the attention it deserves...I just treat it. There is something going on and more research is needed. TCN2 is not particularly uncommon and the studies in terms of moving B12 into the cells is not all that impressive. Against this are the "Frailty Gene" studies where people with this are more likely to become frail.
So, if you went to a nursing home and lined up all people, this gene would be over-represented in those who are considered to be frail.
So, something is going on. Whether the affects are more pronounced with certain other SNPs or perhaps disturbances in the methylation system impact gene expression??? So a combination of genetics and epigenetics? It is over my head. I have stretched my college diploma to the max over the years trying to get well.
The pendulum has swung back. If you read some of my earlier writing, at one time I thought that I had answers. What I have is a few "bricks of knowledge" largely derived from my n=1 experiences. I don't have enough bricks to really build anything. I can,and do, share them with others but I don't know how relevant they are.
I do know that sublingual methylfolate and injections of mB12 have made my life livable again. And I suspect, but can not prove, that this would not have been possible until I took mercury out of the equation.