Quantitative Analyses of Schizophrenia Associated Metabolites in Serum: Serum D Lactate Levels Are Negatively Correlated with Gamma Glutamylcysteine in Medicated Schizophrenia Patients PLOS One Glutathione is often discussed as a key antioxidant within the body. It is present at a cellular level and plays a role in oxidative processes. Levels may be influenced by factors such PDF) Evaluation of serum levels of oxidized and reduced glutathione and total antioxidant capacity in patients with head and neck squamous cell carcinoma How Keeping Glutathione Levels Up Can Benefit Your Health & Your Vitamin D Status GrassrootsHealth