Abstract
This systematic review and meta-analysis evaluated the efficacy and safety of vitamin E supplementation in adults with metabolic dysfunction-associated steatohepatitis (MASH), formerly known as nonalcoholic steatohepatitis (NASH). A comprehensive search of PubMed, Cochrane Library, Embase, and Scopus databases was conducted from inception to May 25, 2025, identifying randomized controlled trials comparing vitamin E versus placebo in MASH patients. After screening 752 records, three high-quality randomized controlled trials were included in the final analysis. The pooled analysis demonstrated that vitamin E significantly reduced serum alanine aminotransferase levels compared to placebo (mean difference (MD): -12.27, 95% confidence interval (CI): -16.66 to -7.89) and aspartate aminotransferase levels (MD: -7.08; 95% CI: -14.93 to 0.76). Vitamin E was associated with significantly higher odds of fibrosis improvement (odds ratio (OR): 1.96, 95% CI: 1.25-3.09) with no heterogeneity observed across studies. However, MASH resolution showed no statistically significant difference between groups (OR: 1.71, 95% CI: 0.69-4.27) with substantial heterogeneity, though sensitivity analysis excluding one study revealed a significant benefit. The studies varied in vitamin E dosing from 300 to 800 mg daily, with two conducted in the United States and one in China. These findings suggest that vitamin E supplementation provides biochemical and histological benefits in MASH patients, particularly in reducing liver enzyme levels and improving fibrosis. However, the limited number of trials and varying outcome definitions highlight the need for larger, standardized multinational studies to establish optimal dosing recommendations and long-term safety profiles.