No , B12 usually has the opposite effect
Some sulfur-rich foods (such as onions and eggs) also contain components that stimulate glutathione production in the body
Rao Q et al (2018) Cryo-EM structure of human ATR-ATRIP complex
Beck RW, Cleary PA, Trobe JD, Kaufman DI, Kupersmith MJ, Paty DW, et al
Two subgroups of cytosolic GSTs have been characterized based upon their interaction with glutathione: the Y-GST group, which uses a tyrosine residue to activate glutathione, and the S/C-GST, which instead uses serine or cysteine residues
found that active GSH metabolism within tumors further suppresses immune responses, such as IFN- signaling and PD-1/PD-L1 interactions, while reducing the number of M1 macrophages and increasing the proportion of M2 macrophages