Vitamin E and Non-alcoholic Fatty Liver Disease: Investigating the Evidence Through a Systematic Review

Nonalcoholic fatty liver disease (NAFLD), now recognized as metabolic dysfunction-associated steatotic liver disease (MASLD), is a common chronic liver condition characterized by hepatic steatosis and inflammation, with an increased risk of developing fibrosis and cirrhosis. This systematic review aims to evaluate the effects of vitamin E supplementation on liver enzymes and histological features in patients with NAFLD/MASLD. We conducted a comprehensive literature search from July 14, 2024, to July 30, 2024, across multiple databases, including PubMed, MEDLINE, ScienceDirect, Europe PMC, the Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and Embase. The included studies consisted of randomized controlled trials (RCTs), clinical trials, and observational studies that evaluated the effects of vitamin E on liver enzymes (ALT and AST) and histological outcomes (steatosis, inflammation, and fibrosis) in adults diagnosed with NAFLD or NASH. A total of 11 studies were analyzed in the final review. Our results indicate that vitamin E supplementation significantly reduces serum aminotransferases and improves histological parameters such as steatosis and inflammation. However, the evidence regarding its efficacy in enhancing fibrosis remains inconclusive, highlighting a significant gap in the current literature. Vitamin E substantially improves liver function and reduces inflammation in patients with NAFLD/MASLD. However, its role in resolving fibrosis remains uncertain, indicating the need for more rigorous, long-term studies to understand its potential to reverse or halt fibrosis progression fully. Further research is required to determine its long-term effects and therapeutic potential, particularly in advanced stages of liver disease.