Prevalence of vitamin D deficiency and insufficiency in Bulgarian patients with chronic hepatitis C viral infection

Abstract

Aims: The present pilot study aimed to determine vitamin D status in Bulgarian patients with chronic HCV infection in respect to the severity of liver disease and response to interferon-ribavirin therapy.

Methods: The study encompassed 296 patients: 161 males (54.4%) aged 42.08 ± 14.87 years, 135 females (45.6%) aged 45.72 ± 14.34 years, 86.5% of them infected with HCV genotype 1. Total 25-hydroxyvitamin-D (25OHD) was determined by liquid chromatography/tandem-mass spectrometric detection.

Results: The median 25OHD level of the studied cohort was 50.40 nmol/L (range: 29.6-71.05). 25OHD deficient (< 25 nmol/L) were 16% of patients, 33% showed profound insufficiency (25-50 nmol/L), another 33% were in the range 50-80 nmol/L (mild insufficiency), the rest 18% were 25OHD sufficient. Significantly lower 25OHD levels were registered in cases with advanced fibrosis compared to those with mild or absent fibrosis (37.10 nmol/L vs. 53.00 nmol/L, respectively, p < 0.05). This association remained unchanged by seasonal variations in 25OHD levels. Inverse relationship was found between 25OHD and HCV-RNA (p < 0.01). Patients with sustained virological response to therapy had significantly higher 25OHD levels, compared to patients who failed to achieve viral eradication (56.90 nmol/L vs. 45.00 nmol/L, p = 0.012).

Conclusion: More than 80% of HCV-infected patients were vitamin D-deficient and -insufficient. The inverse relationship between 25OHD levels and viral load, liver fibrosis and treatment outcomes supports the hypothesis that improvement of vitamin D status may have considerable potential to amend the host defense against HCV infection and response to therapy.

Keywords: Vitamin D deficiency; chronic hepatitis C; liquid chromatography; liver fibrosis.