Biochemical markers of bone metabolism

In this article we review the biochemical basis for markers of bone metabolism and comment on their bone specificity and representativeness for bone tissue. Major developments have recently taken place particularly with respect to markers of bone collagen metabolism; accordingly, they are in the focus of this review. We also attempt to relate the various collagenous and non-collagenous markers to each other and to the phases of the osteoblast phenotype.