Bone markers are laboratory tests that contain the following items: 1) some hormones that regulate bone metabolism, such as a decrease in vitamin D, which proves that the body is deficient and may affect calcium absorption; 2) bone transformation markers, such as bone formation markers, which reflect the activity of osteoblasts, and its decrease for bone synthesis. At the same time, if markers of bone resorption are elevated, such as β-collagen degradation products, these indicators are elevated, proving that bone formation is reduced and bone loss is increased. This is a time when fractures or osteoporosis are likely to occur, a condition more commonly seen in the elderly.