Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and micro-architectural
deterioration of the bone tissues resulting in bone fragility and susceptibility to fracture. It is caused by the decrease of bone
formation and the increase of bone resorption. Both bone formation and resorption can be examined by the circulating
biomolecules. The biomolecules using in determining the bone formation are composed of osteocalcin (OC) in form of Nterminal
midmolecule fragment (N-MID) and undercarboxylated osteocalcin (UcOC). The other bone formation markers are
matrix Gla protein (MGP) and N-terminal propeptide of Type I collagen (P1NP) whereas the biomolecules using in determining
the bone resorption comprises of C-terminal cross-linking telopeptide of Type I collagen (betaCTx), collagen cross-links
molecules which are pyridinoline (PYD) and deoxypyridinoline (DPD). Nevertheless, some vitamins such as vitamin D (Vit
D) and some hormones e.g. parathyroid hormone (PTH) are also affected to the bone quality. To monitor and assess the bone
mass, the normal values of bone markers as well as the relevant biomolecules are important and should be established. The
researchers aimed to investigate the normal values of the interesting bone biomarkers and the relevant biomolecules in the
adult volunteers.

Keywords: Bone markers, Betacrosslap, Biomolecules, Normal values