Osteocalcin, also called bone gla-protein (BGP), is a small, vitamin D and vitamin K-dependent noncollagenous, calcium-binding protein synthesized by osteoblasts and odontoblasts (1-7). Presently, it is the only protein found to be specific for bone and dentin. Although the majority of synthesized osteocalcin associates with bone, a fraction of neosynthesized osteocalcin is released into the circulation (1,5,8). Serum osteocalcin is an important marker of bone turnover in normal subjects and patients (1,3,5). Current understanding of the role of osteocalcin based on radioimmunoassay measurements and there is considerable interest in its determination in serum as a noninvasive index of bone formation(1).