Effects of Vitamin D on Inflammation in Liver Disease

Vitamin D appears to be a critical signaling molecule for macrophages because is needed for activation and differentiation of monocytes/macrophages. From our Preliminary Studies( VA Merit Review Grant), we propose that Vitamin D deficiency may alter the 'pro-inflammatory' ('classically activated') M1 macrophages , characterized by i\] high expression of NOS2, TNF-a, IL-1, IL-6, IL-8, TGF-a, CXCL10, and CCL19; and ii\] minimal expression of arginase 1 and mannose R. The clinical relevance of these findings is suggested by the presence of activated M1 macrophages in liver biopsies from patients with severe drug-induced liver injury (unpublished observations). Prospective vitamin D supplementation studies with appropriate endpoints are needed to define the role of vitamin D on inflammation in patients with chronic liver diseases.