Vitamin D levels do not predict the stage of hepatic fibrosis in patients with non-alcoholic fatty liver disease: A PRISMA compliant systematic review and meta-analysis of pooled data

Table 2 Inclusion and exclusion criteria of studies on vitamin D in non-alcoholic fatty liver disease

Inclusion criteria

Patients ≥ 18 yr

Studies that evaluated vitamin D in NAFLD

Studies that evaluated the liver fibrosis stage, only based on liver biopsy

Studies that reported serum or plasma 25(OH)D levels

Exclusion criteria

Age < 18 yr

Liver diseases other than NAFLD

Studies that used non-invasive methods to evaluate liver fibrosis

Studies with inadequate data

25-OH(D): 25-hydroxyvitamin D; NAFLD: Nonalcoholic fatty liver disease.