Decreased circulating vitamin D reflects adverse outcomes of hepatitis C virus infection: A systematic review and meta-analysis

Abstract

Objectives: This study aimed to clarify associations of circulating vitamin D and its status with severity of HCV infection.

Methods: We performed systemic literature search in PubMed, Scopus, and Cochrane library databases from inception until the end of December 2019 with terms related to vitamin D and hepatitis C.

Results: A total of 28 studies consisting of 7736 HCV-infected patients and 14061 control subjects without liver diseases were included. Compared to controls, circulating vitamin D levels were significantly lessened in HCV-infected patients (mean difference, MD=-14.15, 95% CI: -20.51 to -7.80). Remarkably decreased circulating vitamin D was found in the patients with severe fibrosis (MD=-3.38, 95% CI: -4.51 to -2.25), non-achieving SVR (MD=-2.99, 95%CI: -5.55 to -0.42), and advanced inflammation (MD=-4.68, 95% CI: -8.50 to -0.86). Low vitamin D status (<20 ng/mL) was significantly associated with increased odds of HCV infection (pooled OR=2.41, 95% CI: 1.48 to 3.95). Besides, HCV-infected patients with low vitamin D status showed significantly escalated odds of severe fibrosis and non-achieving SVR (pooled OR=1.70, 95% CI: 1.27 to 2.26; pooled OR=2.04, 95% CI: 1.62 to 2.57, respectively).

Conclusion: HCV-infected patients with declined circulating vitamin D levels were associated with severe fibrosis, non-achieving SVR, and advanced inflammation.

Keywords: Hepatic inflammation; Hepatitis C; Liver fibrosis; Sustained virologic response; Vitamin D.