Background and aim: To explore associations between serum 25-hydroxyvitamin D(3) [25(OH)D] concentrations and liver histology in patients with non-alcoholic fatty liver disease (NAFLD).
Methods and results: We studied 60 consecutive patients with biopsy-proven NAFLD, and 60 healthy controls of comparable age, sex and body mass index (BMI). NAFLD patients had a marked decrease in winter serum 25(OH)D concentrations (51.0+/-22 vs. 74.5+/-15 nmol/L, P<0.001) compared with controls. Metabolic syndrome (MetS; as defined by the Adult Treatment Panel III criteria) and its individual components occurred more frequently among NAFLD patients. The marked differences in 25(OH)D concentrations observed between the groups were little affected by adjustment for age, sex, BMI, creatinine, calcium, homeostasis model assessment (HOMA)-insulin resistance, and the presence of the MetS. Interestingly, among NAFLD patients, decreased 25(OH)D concentrations were closely associated with the histological severity of hepatic steatosis, necroinflammation and fibrosis (P<0.001 for all) independent of age, sex, BMI, creatinine, calcium, HOMA-insulin resistance, and presence of the MetS.
Conclusions: Compared with controls, NAFLD patients have a marked decrease in serum 25(OH)D concentrations, which is closely associated with histopathological features of NAFLD. Further investigation into whether vitamin D(3) may play a role in the development and progression of NAFLD appears to be warranted.