Iron-overloaded mice exhibit decreased bone mass, increased resorption, and increased deposition of osteoid. (A) First row: No changes in MAR and BFR by double-label technique in the iron-overloaded mice compared with placebo. Decreased BV/TV (von Kossa stain) with iron excess. Second row: Increased osteoclast surface (Goldner trichrome stain) and increased osteoclast numbers (no/mm) by TRAP in iron-treated mice. No changes were found in osteoblast numbers between placebo and iron-treated mice using stain for procollagen type I. Increased osteoid was present in the iron-treated animals. Data are mean ± SD. *P < .05. **P < .01. (B) Increased expression of genes associated with bone resorption (CTK, OPG, and RANKL) in iron-overloaded mice. No changes in expression of OC and OPN. Data are mean ± SD. *P < .01.