Bone Health
Bone health refers to the strength, density, and metabolic activity of the skeleton. Bones are living tissues that constantly undergo remodeling, a process where old bone is broken down and new bone is formed. This cycle maintains skeletal strength, repairs microscopic damage, and helps regulate essential minerals such as calcium and phosphorus.
When the balance between bone formation and bone breakdown becomes disrupted, it can lead to conditions such as osteopenia, osteoporosis, fractures, or metabolic bone disorders. Laboratory tests known as bone health biomarkers help measure these processes and provide insight into how actively bone tissue is being formed and resorbed.
These biomarkers are often referred to as bone turnover markers, because they reflect the rate at which bone is continuously renewed.
What Are Bone Turnover Markers?
Bone turnover markers are laboratory biomarkers that measure the biological activity of bone remodeling. They provide information about how quickly bone tissue is being broken down and rebuilt.
Bone turnover markers generally fall into three main groups:
-
Bone formation markers – indicators of new bone production by osteoblasts
-
Bone resorption markers – indicators of bone breakdown by osteoclasts
-
Hormonal regulators of bone metabolism – hormones that control calcium, phosphate, and vitamin D balance
Evaluating these markers together helps clinicians better understand skeletal metabolism and identify abnormalities in bone turnover.
Bone Formation Markers
Bone formation markers reflect the activity of osteoblasts, the specialized cells responsible for building new bone tissue.
These biomarkers help evaluate how actively bone is being produced and mineralized.
Markers in this category include:
-
Alk Phosphatase, Bone Specific
-
Osteocalcin, Serum
Elevated levels may occur when bone formation is increased, such as during bone growth, fracture healing, or high-turnover bone disorders.
Bone Resorption Markers
Bone resorption markers measure the activity of osteoclasts, the cells responsible for breaking down old bone tissue.
One of the most widely used bone resorption markers is:
-
C-telopeptide (CTX)
Higher CTX levels may indicate increased bone breakdown, which can occur in conditions such as osteoporosis, hyperparathyroidism, or high bone turnover states.
Hormones That Regulate Bone and Mineral Metabolism
Several hormones help control the balance of minerals needed for healthy bones.
These hormonal regulators influence calcium absorption, phosphate balance, and bone remodeling.
Key regulators include:
-
Parathyroid Hormone (PTH), Serum
-
Parathyroid Hormone, Intact
-
FGF-23
Disruptions in these hormones can affect bone density and mineral balance, sometimes leading to metabolic bone disease.
Why Bone Health Biomarkers Are Tested
Bone turnover markers and related biomarkers may be tested to help evaluate or monitor:
-
Osteoporosis
-
Osteopenia
-
Abnormal bone turnover
-
Parathyroid disorders
-
Vitamin D deficiency
-
Chronic kidney disease–related bone disorders
-
Abnormal calcium or phosphate levels
Because bone remodeling is a continuous process, measuring these biomarkers can help detect metabolic changes in bone before structural damage becomes visible on imaging tests such as bone density scans (DEXA).
Understanding Your Bone Health Results
Bone health biomarkers are typically interpreted together with other laboratory tests and imaging studies. Evaluating multiple markers of bone formation, bone resorption, and mineral regulation provides a more complete picture of skeletal health.
When abnormal results are detected, additional testing may help identify underlying causes and guide treatment strategies aimed at protecting long-term bone strength.
Show more
Biomarkers included in this panel:
What Is Bone-Specific Alkaline Phosphatase? Bone-specific alkaline phosphatase (BAP or BSAP) is an enzyme produced primarily by osteoblasts, the cells responsible for building new bone. It is a specific isoenzyme of the broader alkaline phosphatas
Learn moreC-telopeptide (CTX) is a biomarker that reflects the rate of bone resorption, the natural process where old or damaged bone tissue is broken down and recycled. CTX levels help evaluate bone turnover and can be useful in assessing conditions like oste
Learn moreWhat is FGF-23? FGF-23, or fibroblast growth factor 23, is a hormone-like protein that plays a critical role in phosphate and vitamin D metabolism. It is primarily produced by bone cells (osteocytes and osteoblasts) and acts mainly on the kidneys
Learn moreWhat Is Osteocalcin? Osteocalcin is a protein hormone produced almost exclusively by osteoblasts, the specialized bone-forming cells. It plays a critical role in bone formation, mineralization, and calcium regulation. Osteocalcin is considered one
Learn moreParathyroid hormone (PTH) helps the body maintain stable levels of calcium in the blood. It is part of a feedback loop that includes calcium, PTH, vitamin D, and, to some extent, phosphorus (phosphate) and magnesium. Conditions and diseases that disr
Learn moreParathyroid Hormone (PTH), Intact, plays a crucial role in maintaining a delicate balance in our body's calcium and phosphorus levels, directly impacting bone health. This hormone, produced by the parathyroid glands located behind the thyroid gla
Learn more