The Relationship between Antioxidant Vitamins and Mental Disorders: A Meta-analysis

Abstract

Background: Mental disorders are associated with oxidative stress. Antioxidant vitamin A, C and E possess antioxidant properties. Nevertheless, the association between antioxidant vitamins and mental disorders remains ambiguous. Methods: This meta-analysis compared the levels of dietary and blood vitamins A, C, and E between patients with attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), Depression, and schizophrenia (SZ) and healthy controls. Furthermore, a Mendelian randomization (MR)post-meta-analysis approach was employed to explore the causal relationships between these antioxidant vitamins and mental health conditions. Results: Dietary analysis indicated that patients with Depression exhibited significantly lower intakes of vitamin A (SMD: -0.13, 95%CI: -0.21, -0.05, P < 0.01), vitamin C (SMD: -0.18, 95%CI: -0.24, -0.13, P < 0.01), vitamin E (SMD: -0.16, 95%CI: -0.28, -0.04, P = 0.01), and carotenoids (SMD: -0.17, 95%CI: -0.20, -0.14, P < 0.01) compared with controls. Blood analysis revealed that patients with Depression had decreased blood levels of vitamin A (SMD = -0.18, 95%CI: -0.29, -0.06, P < 0.01), vitamin C (SMD = -0.52, 95%CI: -0.94, -0.10, P = 0.01), and vitamin E (SMD = -0.77, 95%CI: -1.39, -0.16, P = 0.01). Similarly, patients with SZ demonstrated reduced blood level of vitamin C (SMD = -0.85, 95%CI: -1.49, -0.21, P = 0.01) and vitamin E (SMD = -0.92, 95%CI: -1.21, -0.62, P < 0.01). However, no significant differences were found in the dietary or blood antioxidant vitamins in patients with ADHD and ASD. MR post-meta-analysis identified a causal relationship between SZ and vitamin C. Conclusion: Patients with Depression had lower levels of dietary and blood vitamins A, C, and E. Similarly, SZ had reduced blood levels of vitamins C and E.