6-ECDCA-d 4 serves as an internal standard for quantifying 6-ECDCA (Item No. 50 = 99 nM). Via FXR, it modifies gene expression, offering protection against cholestasis and liver fibrosis in animal models. Additionally, it promotes adipocyte differentiation and enhances insulin signaling in mature adipocytes. In _ApoE -/-_ mice, 6-ECDCA mitigates vascular calcification due to chronic kidney disease without impacting atherosclerosis development.