Association of Vitamin D Deficiency with Metabolic Dysfunction-Associated Steatohepatitis (MASH): A Cross-Sectional Analytical Study

Background: “Metabolic dysfunction-associated steatohepatitis (MASH)” is a progressive inflammatory disease associated with obesity, insulin resistance, type 2 diabetes mellitus and dyslipidemia. The link between vitamin D and severity of MASH is not fully examined although vitamin D has been recognized to drive hepatic inflammation and progression of fibrosis. This study aimed to assess the prevalence of vitamin D deficiency in patients with MASH and to correlate with the metabolic parameters and the severity of the disease. Material and Methods: This was a cross-sectional analytical study conducted at the hospital from January 2024 to December 2025 with the study group consisting of 180 adults age range 18-65 years with diagnosis of MASH. Diagnosis was made based on clinical assessment, biochemical parameters, ultrasonography and the FibroScan results according to the current criteria of MASLD. 25-hydroxyvitamin D [25(OH)D] levels were defined as deficient (< 20 ng/mL), insufficient (20–30 ng/mL), and sufficient (>30 ng/mL). Anthropometric parameters, glycemic profile, lipid profile, liver enzymes, HOMA-IR and liver stiffness index were assessed. Predictors of severe MASH were identified using a multivariate logistic regression analysis. Results: 68.9% of the patients showed the presence of vitamin D deficiency, 21.1% insufficiency, and 10.0% sufficiency. Deficient patients had significantly higher BMI (p=0.003), HOMA-IR (p<0.001), ALT (p=0.002), AST (p=0.005), triglycerides (p=0.01), and liver stiffness measurements (p=0.001). Vitamin D deficiency was more prevalent among advanced fibrosis patients as compared to more normal patients (42.7 % vs 16.7 % respectively, p<0.001). Severe MASH (aOR: 95% CI: 1.61–4.98, p<0.001) was independently predicted by vitamin D deficiency. Conclusion: Vitamin D deficiency is greatly common in MASH and is an independent predictor for metabolic dysfunction and hepatic inflammation and severity of fibrosis. Treatment and correction of vitamin D deficiency as a routine part of overall care for MASH can be beneficial.

Keywords: Vitamin D deficiency; MASH; Hepatic fibrosis; Insulin resistance.