Bone tissue was essentially considered as a mechanical structure; however is now well known that is the site of permanent bone remodelation. In addition, bone functions as an endocrine gland producing osteocalcin, which in turn interacts with other tissues, such as fat, pancreas and gastrointestinal tract. As a consequence, osteocalcin intervenes into glucose metabolism, peripheral insulin sensitivity and inflammatory process. In sum, bone may be accepted as an endocrine gland.