To sum up, the results of the meta-analysis suggest that treatment with IGU in patients with RA is associated with improved lumbar-spine BMD, increased serum OPG, decreased RANKL, increased serum markers of bone formation (N-MID and T-P1NP), and decreased serum marker of bone resorption (β-CTX). Here, CYP27A1 is linked to rheumatoid arthritis.