The Role of Vitamins in Non-Alcoholic Fatty Liver Disease: A Systematic Review

Abstract

Non-Alcoholic Fatty Liver Disease (NAFLD) emerged as the most prevalent liver disorder contributing significantly to disease burden worldwide. It manifests as a broad spectrum of hepatic damage with varying severity ranging from less serious steatosis to a more severe Non-Alcoholic Steatohepatitis (NASH), with or without fibrosis, cirrhosis, and hepatocellular carcinoma. Vitamins, on the other hand, are micronutrients that are vital for healthy well-being. Some studies have linked liver diseases with hypovitaminosis; however, there are still some gaps about the basis of their correlation. Hence, this systematic review aims to discuss the role of vitamins in the pathogenesis of NAFLD and explore their hepatoprotective potential that may benefit clinicians in managing this condition. This systematic review searched for studies indexed in the PubMed, PubMed Central, Medline, Google Scholar, and ScienceDirect databases. Inclusion and exclusion criteria were applied, duplicates were removed, and meticulous screening of articles was done systematically. Out of 729 unique studies generated using the search strategy, 17 were finally included after thorough review and quality appraisal. NAFLD is not simply an outcome of insulin resistance and metabolic derangements; instead, it is a disease with complex underlying pathogenesis. Moreover, vitamin deficiency has been associated with NAFLD development and increased susceptibility to more severe liver damage. Derangement in vitamins correlates to the lipotoxic hepatic environment, altered immune system, unwarranted inflammation, oxidative stress, gene mutations, epigenetic modification, and gut dysbiosis seen in NAFLD. As they influence several pathophysiologic processes in the liver, vitamins A, B3, B6, B9, B12, C, D, and E are promising potential options that can impact NAFLD management. However, more well-designed studies conducted in the human population are still necessary to establish their efficacy and safety as therapeutic agents.

Keywords: nafld; non-alcoholic fatty liver disease; vitamin a; vitamin b; vitamin c; vitamin d; vitamin e; vitamin k; vitamins; vitamins and nafld.

Figure 1. PRISMA Flow Diagram

PRISMA - Preferred Reporting Items for Systematic Review and Meta-analysis, MeSH - Medical Subject Headings

Figure 2. Pathophysiologic Processes in NAFLD Development and Progression

Adapted From Source: Chen et al. [9] and Nagashimada et al. [10] TNF-α - tumor necrosis factor-alpha, IL-6 - interleukin-6, M1 - classically activated macrophages, M2 - alternatively activated macrophages, NASH - Non-Alcoholic Steatohepatitis, NAFLD - Non-Alcoholic Fatty Liver Disease