BACKGROUND: Vitamin D is a fat-soluble sterol derivative that is predominantly synthesized in the liver and has multiple functions. The accumulative data showed that the clinical manifestations and prognosis of chronic liver diseases are associated with serum vitamin D levels.
DATA SOURCES: A PubMed and Google Scholar search using terms: "vitamin D", "25(OH)D", "liver disease", "viral hepatitis", "non-alcoholic fatty liver disease", "liver fibrosis", "cirrhosis", "hepatocellular carcinoma" and "autoimmune liver disease" was performed, and relevant articles published in English between January 2000 and March 2014 were reviewed. Full-text publications relevant to the field were selected and relevant articles from reference lists were also included.
RESULTS: The insufficiency or deficiency of vitamin D is common in various kinds of chronic liver diseases including viral hepatitis B and C. Serum 25-hydroxyvitamin D and vitamin D receptors are possibly interrelated with the incidence, treatment and prognosis of diseases. Though the evidence of vitamin D supplementation in viral hepatitis and associated liver diseases is still limited, there is great potential to apply this adjuvant therapy to improve the treatments.
CONCLUSIONS: Although the exact role and mechanisms of vitamin D have not been fully elucidated in chronic liver diseases, it is potentially beneficial in the treatment of chronic liver diseases. Further mechanistic studies are needed to validate its clinical application.