What is secreted by osteoblasts during bone deposition?

During bone deposition, osteoblasts secrete several key components, primarily osteoid, which is an unmineralized organic matrix composed of collagen and other proteins. They also produce enzymes and factors that facilitate the mineralization of the osteoid, such as alkaline phosphatase. Additionally, osteoblasts secrete signaling molecules like osteocalcin that play a role in regulating bone metabolism and mineralization.