Bone resorption markers are -
Markers of bone resorption

Urine & serum cross-linked N telopeptide
Urine & serum cross-linked C telopeptide
Urine total free deoxypyridinoline
Urine hydroxyproline
Urine hydroxylysine glycosides
Serum tartrate-resistant acid phosphatase
Serum bone sialoprotein
Serum propeptide of type I procollagen
Osteocalcin
Urine total free deoxypyridinoline
Free glutamic acid cross linkage