To investigate the effect of menatetrenone on bone turnover in postmenopausal patients with osteoporosis. One month of menatetrenone therapy enhanced the secretion and gamma-carboxylation of osteocalcin. Moderate increases of bone resorption and formation markers were observed after 6 months. These changes may contribute to fracture prevention in patients with osteoporosis.

Inclusion criteria:

• A diagnosis of osteoporosis was made according to the Year 2000 version of the Diagnostic Criteria for Osteoporosis proposed by the Japanese Society for Bone and Mineral Research.
• These criteria state that patients with a lumbar bone mineral density (BMD)<70% of the young adult mean or patients with pre-existing osteoporotic fractures and a lumbar BMD<80% of the young adult mean can be diagnosed as having osteoporosis.

Exclusion criteria:

• Patients with secondary osteoporosis (e.g., due to major gastrointestinal surgery, steroid therapy, rheumatoid arthritis, premenopausal bilateral oophorectomy, renal dysfunction, and thyroid dysfunction ).
• Patients taking medications that could affect bone turnover (such as bisphosphonates, estrogen, calcitonin, SERM, active vitamin D3, or Warfarin) were excluded.