Prospective study on the relation between serum vitamin D levels and liver cirrhosis risk

OBJECTIVE: To explore the relation between serum vitamin D (25(OH)D) concentrations and liver cirrhosis.

METHODS: A nested case control study was designed based on the Nutrition Intervention Trial (NIT) cohort, from which non-degraded serum samples and complete baseline and follow-up data were available for 282 individuals diagnosed with liver cirrhosis and 564 healthy controls. The serum samples were tested by enzyme-linked immunosorbent assay to detect and quantify 25(OH)D, as well as hepatitis B virus surface antigen and core antibody and hepatitis C virus antibody. The study participants were divided into four groups according to quartile range of 25(OH)D concentration and logistic regression modeling was used to evaluate the relation with liver cirrhosis risk by estimating odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS: The liver cirrhosis group had a significantly lower concentration of 25(OH)D than the control group (median and quartile range in nmol/L, cases: 15.3 and 13.8; controls: 20.2 and 16.6; t = 5.169, P = 0.002). When the first interval was set as the reference level, the ORs(95% CIs) of the second, third, and fourth intervals were: 0.495(0.333 - 0.736), 0.452(0.303 - 0.675), and 0.349(0.231- 0.527). After adjusting the analysis for the presence of pathogenic-related confounding factors, the ORs(95% CIs) of the second, third, and fourth intervals were: 0.499(0.328 - 0.759), 0.427(0.278 - 0.654), and 0.344(0.222-0.532). The 25(OH)D level was inversely correlated with risk of liver cirrhosis (Chi2 = 25.200, P < 0.001).

CONCLUSION: Risk of liver cirrhosis increases as 25(OH)D serum concentration decreases. Vitamin D might function as a protective factor against development of cirrhosis.