25-Vitamin D levels in chronic hepatitis C infection: association with cirrhosis and sustained virologic response.

backgroundLow serum 25-Vitamin D levels are associated with advanced fibrosis in hepatitis C infection. Vitamin D supplementation has been hypothesized to augment response rates to interferon-based therapy. To date, no investigation has evaluated vitamin D levels during direct-acting antiviral therapy. We aimed to evaluate the prevalence of vitamin D deficiency in cirrhotic and non-cirrhotic cohorts, the predictive value of pretreatment levels for a sustained virologic response, and the changes in 25-OH vitamin D levels during direct-acting antiviral therapy.

methodsTwo hundred eighteen patients with chronic hepatitis C who completed direct-acting antiviral therapy were consecutively enrolled. Vitamin D levels were measured using chemiluminescence immunoassay, prior to initiation and at completion of therapy. Advanced liver fibrosis (cirrhosis) was determined by biopsy, FibroSURE blood test, or imaging.

resultsA sustained virologic response was achieved in 79% (n=172) of patients, with 19% (n=44) relapsing. A total of 123 (56.4%) patients were cirrhotic. The prevalence of Vitamin D deficiency (10-20 ng/mL) and severe deficiency (<10 ng/mL) was significantly higher in cirrhotic patients (P=0.04). Pre-treatment vitamin D levels in cirrhotic patients were negatively correlated with Model for End-Stage Liver Disease score, total bilirubin and INR (P<0.05). Neither pretreatment vitamin D level nor the change during therapy was associated with an increased rate of sustained virologic response.

conclusionsThe prevalence of vitamin D deficiency is higher in hepatitis-C-related cirrhotic cohorts compared to non-cirrhotic patients and correlates with components of hepatic function. Neither pretreatment vitamin D level nor the change during therapy was associated with an increased rate of sustained virologic response.