Influence of vitamin D on liver fibrosis in chronic hepatitis C: A systematic review and meta-analysis of the pooled clinical trials data

Figure 1 Vitamin D metabolism. Vitamin D has diverse influences throughout the body as vitamin D receptors present on virtually every cell. The actions of vitamin D can be subdivided into two larger categories: Calcemic and non-calcemic actions. The non-calcemic actions of vitamin D are legion and have been reviewed elsewhere[6,54-58]. Reproduced with permission[6].

Figure 2 Flowchart of study selection process. Eighteen hundred and twelve articles were identified using PubMed (n = 468)/EMBASE (n = 1269)/Cochrane (n = 23)/Scopus (n = 42)/LILACS (n = 10) search engines. Detailed evaluation of the articles by at least two independent reviewers (total of three) narrowed the studies to twelve (n = 2521) based upon inclusion and exclusion criteria as listed in Table 1.

Figure 3 Meta-analysis of the pooled data from the 12 included studies. The odds ratio for severe fibrosis comparing low vitamin D levels was estimated by meta-analyzing studies including a total of 2521 patients. Details concerning the analytic strategy are provided in the Materials and Methods section.