Vitamin E, Alpha-Tocopherol, and Its Effects on Depression and Anxiety: A Systematic Review and Meta-Analysis
What this study found
Vitamin E supplementation showed potential for reducing depressive symptoms, but the anxiety findings were inconclusive. Several small trials reported benefit, including Rees 2008 for depression (HDRS SMD -1.08, 95% CI -1.92, -0.25), Jamilian 2018 (BDI SMD -1.16, 95% CI -1.84, -0.49), and Malaguarnera 2016 (BDI SMD -2.69, 95% CI -3.38, -1.99). Other studies were null or borderline, such as Lu 2009 (SMD -0.24, 95% CI -0.58, 0.10) and Carlsson 2002 (SMD -0.64, 95% CI -1.33, 0.04), and anxiety results ranged from positive to no clear benefit. Overall, the authors concluded that vitamin E may…
- Study & population
- Systematic review and meta-analysis of 12 adult studies examining depression or anxiety outcomes in people with symptoms or risk of mood disorders.
- Intervention
- Oral vitamin E supplementation, reported as alpha-tocopherol or tocopherol, was evaluated across multiple regimens ranging from 80 mg/day to 2000 IU/day for 6 weeks to 3 years.
- Key limitation
- The evidence base was small and heterogeneous, with varied populations, outcome scales, doses, and treatment durations.
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Open PDFOriginal abstract
Background: Recently, it has been discovered that anti-inflammatory and anti-oxidative pathways play a role in depression and anxiety. Lower serum levels of antioxidants, such as vitamin E, have been implicated in both depression and anxiety. Methods: This PROSPERO-registered systematic review (Reference: CRD42021260058) is reported according to PRISMA guidelines. PubMed, EMBASE, CENTRAL, PsycINFO, and CINAHL were searched from inception to June 2021. Results: Twelve studies were included in this systematic review, and nine in meta-analysis of vitamin E versus placebo. For depression, meta-analysis of 354 participants showed a standardised mean difference of –0.88 (95% CI: –1.54, –0.21; I2 = 87%) favouring vitamin E. For anxiety, meta-analysis of 306 participants showed a standardised mean difference of –0.86 (95% CI: –2.11, 0.40; I2 = 95%) favouring vitamin E. Three of the studies involved a pure comparison of vitamin E against placebo, while others included constituents such as omega-3 fatty acids. Nine of the studies were at low risk of bias, two had some concerns, and one was at high risk of bias. Conclusion: Vitamin E supplementation has shown inconclusive results in ameliorating both depression and anxiety. Containing a reassuring safety profile and low cost, future studies would be of promise, and they would benefit from both larger sample sizes and from excluding other constituents, such as omega-3 fatty acids, from experimental and comparator arms.