Bone specific alkaline phosphatase

You should get a bone-specific alkaline phosphatase test if your total ALP is high and the source is unclear, or if you have bone pain, deformities, or frequent fractures. It is also recommended for suspected Paget's disease, osteomalacia, bone metastases, or hyperparathyroidism, and for monitoring osteoporosis treatment.

For monitoring, give samples at the same time of day each time. Avoid strenuous exercise beforehand, and inform your doctor about recent fractures, pregnancy, osteoporosis medicines, or biotin supplements.

Fasting is usually not required for a bone-specific alkaline phosphatase test, as meals have little effect on BAP levels. However, some labs recommend an overnight fast, so follow their instructions. If other tests that need fasting are ordered alongside it, you may need to fast for 8–12 hours.