Journal of Research in Medical Sciences1735-1995238201808251082610826EN20180820<span class="fontstyle0">Vitamin D has an important role in bone metabolism but recently has been recognized as an immunoregulator, and this has led to investigations on the e?ect of Vitamin D supplementation in various autoimmune diseases and its anti?in?ammatory e?ects. Tere is some evidence that Vitamin D can regulate gastrointestinal in?ammation. In addition, previous studies have shown that Vitamin D can a?ect the gut microbiome. Te aim of this review is to evaluate the e?ect of Vitamin D on in?ammatory processes, especially<br />its relation to the in?ammatory bowel disease (IBD) and gut microbiome. Tere is some evidence that Vitamin D can regulate gastrointestinal in?ammation, with epidemiological studies showing that individuals with higher serum Vitamin D have a lower incidence of IBD, particularly Crohn’s disease. Vitamin D changes transcription of cathelicidin and DEFB4 (defensin, beta 4) that can a?ect the gut microbiome. Several cell types of the immune system express Vitamin D receptor, and hence the use of Vitamin D in immune regulation has some potential. Furthermore, Vitamin D defciency leads to dysbiosis of gut microbiome and reported to<br />cause severe colitis. Vitamin D supplementation is low cost and available and can be a therapeutic option.</span> <br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;" />http://jrms.mui.ac.ir/index.php/jrms/article/view/10826http://jrms.mui.ac.ir/index.php/jrms/article/download/10826/5657