On Importance of Glutathione in Cobalamin metabolism

For those struggling with B12 deficiency:

Remember about importance of Glutathione in Cobalamin metabolism:

Aquacobalamin is one of the major forms of vitamin B(12) isolated from mammalian cells.

Aquacobalamin and the thiolate forms of glutathione are the precursors of glutathionylcobalamin (GSCbl, a precursor to the formation of the two coenzyme forms of vitamin B(12), adenosylcobalamin and methylcobalamin) in mammalian cells.

Under biological conditions the formation of GSCbl from aquacobalamin and glutathione is essentially irreversible; upon entering cells, any free (protein-unbound) aquacobalamin could be rapidly and irreversibly converted to GSCbl. (R1)

What that says literally: before B12 can become adenosyl- or methyl- form inside the cell, it needs to become glutathionylcobalamin first.

If you’re in high oxidative stress and your GSH is depleted, that’s one more reason for functional B12 deficiency. I wonder why GRJ is not talking about that.