It's described as the "master antioxidant" because it does two jobs at once: it neutralises free radicals directly, and it helps recycle other antioxidants like vitamin C and vitamin E so they can keep working
First, it focused on the ACC but did not investigate other brain regions, based on the assumption of its involvement in the pathology of autism
Additionally, a randomized, double-blind, placebo-controlled trial in 2,588 healthy older adults with mild hyperhomocysteinemia found that daily supplementation with 500 g of vitamin B 12 and 400 g of folic acid for two years reduced blood homocysteine concentrations but had no benefit on depressive symptoms in those with or without depressive symptoms at baseline (110)
doi:10.1016/j.freeradbiomed.2016.01.029 120. Umesawa, Y., Matsushima, K., Atsumi, T., Kato, T., Fukatsu, R., Wada, M., & Ide, M
It signals fibroblasts to produce collagen and elastin, accelerates wound and tissue remodeling, and shifts gene expression toward repair