The Effect of Vitamin K2 on Bone Turnover

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.