BGLAP and osteoporosis: The biomarkers of bone metabolism, namely, osteocalcin (BGP), parathyroid hormone (PTH), 25-OH VD, and type 1 procollagen amino terminal extender peptide (P1NP) are sensitive, specific, and non-invasive clinical aids to the diagnosis of osteoporosis, and can enable accurate evaluation of bone turnover at the level of intact bone tissue (Balsan et al., 1986).