association between vitamin d deficiency and the severity of chronic liver disease and liver cirrhosis: systematic literature review

background vitamin d deficiency is believed to cause variety of abnormalities such as liver stiffness and fibrosis. it is also shown that vitamin d deficiency may result in chronic liver disease or liver cirrhosis. in this study, we aimed to systematically review the literature wherein the relationship between vitamin d deficiency and the severity of chronic liver disease or liver cirrhosis had been investigated. materials and methods pubmed, scopus, and google scholar were searched using the following search method (((vitamin d deficiency or vitamin d insufficiency or insufficient vitamin d)) and (chronic liver disease or chronic hepatitis or cirrhosis or liver cirrhosis)) and (severity or intensity) to evaluate the role of vitamin d deficiency or vitamin d inadequacy in the occurrence and severity of chronic liver disease. articles were collected and the data were extracted. results totally, 641 articles were found through searching the databases and reference list scanning. of the collected documents, only 19 articles with 4895 studied patients were included and analyzed. the results of this study showed that almost 80% of patients with chronic liver disease had severe vitamin d deficiency. conclusion vitamin d deficiency is associated with the occurrence of chronic liver disease. the severity of liver cirrhosis is also associated with the level of 25(oh)d in progressive liver disease.