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Osteocalcin (Bone-specific Alkaline Phosphatase Activity) in Serum

Published: August 9, 2026Updated: August 16, 2026

This test measures the activity of alkaline phosphatase specific to bone tissue, helping assess bone formation and metabolic health.

Quick summary

["Your bone health may be evaluated by this test, which reflects new bone growth activity."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
36038-8
Short code
XR tomo Knee
Synonyms
XR tomo Knee
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr-tomography
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

Osteocalcin is a protein produced by osteoblasts (bone-forming cells). Measuring its activity helps doctors evaluate how actively your bones are forming new tissue. This test is often used alongside other markers to monitor conditions affecting bone metabolism, such as osteoporosis or metabolic bone diseases.

Why It’s Ordered

Your healthcare provider may order this test if you have symptoms or risk factors for bone disorders, such as fractures, slow healing after injury, or unexplained bone pain. It may also be used in research or clinical trials studying bone health or metabolic conditions.

Common Uses in Clinical Practice

Osteocalcin activity can help diagnose or monitor conditions like osteoporosis, Paget’s disease, or metabolic bone disorders. It may also be used in the evaluation of patients with hyperparathyroidism or other conditions affecting calcium metabolism.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before drawing blood. Wear a loose shirt for easy access to your arm.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Osteocalcin Activity

Frequently asked questions

How long does it take to get results from this test?
Results are typically available within 1–3 business days, depending on your lab’s processing schedule. Your healthcare provider will discuss the findings with you during your follow-up visit.
Can I take any medications before this test?
Some medications, like certain steroids or calcium supplements, may affect bone metabolism. If you’re on long-term medication, discuss it with your provider before the test.
Is there anything I should avoid doing after the test?
There are no strict restrictions after the test, but avoid heavy exercise or strenuous activity for 24 hours to prevent bruising at the needle site.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy