PTH and osteoporosis: Bone-turnover biomarkers [including alkaline phosphatase (ALP), β-carboxy terminal crosslinked telopeptide of type 1 collagen (β-CTX), N-terminal midfragment of osteocalcin (N-MID)] and related biomarkers [including serum calcium, serum phosphorus (P), 25 hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), and calcitonin] can be used as a risk assessment tool for post-menopausal osteoporosis, and some studies even suggested that β-CTX to be better than BMD in predicting senile fractures (13, 14).