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

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.