In people with NAFLD, vitamin D supplementation may improve insulin resistance, marked by a reduction of HOMA-IR. 

A study was carried out to determine the impact of additional vitamin D therapy for improving insulin resistance in people suffering from non-alcoholic fatty liver disease (NAFLD).

Databases like Science Direct, PubMed, COCHRANE, and Google Scholar were explored to discover relevant literature. Utilizing the fixed effect model or random effect model, the obtained studies were examined. A total of 7 eligible studies and 735 participants were incorporated in this systematic review and meta-analysis.

In NAFLD people, supplementing vitamin D was found to enhance insulin resistance, characterized by decreased Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), with a pooled mean difference of - 1.06. Treatment with vitamin D raised vitamin D serum levels with a pooled mean difference of 17.45. Additionally, it minimized ALT levels, with a pooled mean difference of - 4.44. Regarding AST levels, no effect was witnessed.

Vitamin D therapy offers promising effects on the improvement of insulin resistance in people with NAFLD and can serve as a promising adjunctive therapy for the management of NAFLD.