Journal of Biological Chemistry 285 , 3315433164, doi: 10.1074/jbc.M110.143685 (2010)
With age as a covariate, the Spearman rho values remained practically unchanged (differed by less than 0.02) regardless of if we excluded or included the covariate, separately for all 4 conditions [Hypothyroidism/CFS x Before/After L-carnitine]
Perlmutter measured both glutathione levels and oxidized glutathione levels primarily in the substantia nigra (portion of the brain most affected in PD) in PD patients and in control groups
Qiu et al., 2017)
It also helps recycle homocysteine back into methionine, a step that requires vitamin B12 (cobalamin)
References: Nagele P., Palanca B.J., Gott B., Brown F., Barnes L., Nguyen T., Xiong W., et al