Procollagen type 1 N-terminal propeptide (P1NP), and C-terminal telopeptide of type 1 collagen (CTX) are biomarkers of bone loss in systemic lupus erythematosus (SLE) [9], rheumatoid arthritis [10] and dermatomyositis [11]. Here, CYP27A1 is linked to systemic lupus erythematosus.