title: Effect of vitamin K2 treatment on carboxylation of osteocalcin in early postmenopausal women.
abstract: OBJECTIVE
  We examined the serum level of undercarboxylated osteocalcin (uc OC), which is a sensitive marker of vitamin K status, and levels of bone turnover markers in early postmenopausal women receiving vitamin K2 treatment with or without vitamin D3.
  
  
  METHODS
  Thirty-four postmenopausal women with a mean age of 53 years whose bone mineral density (BMD) was less than 0.809 g/cm2 (osteopenia and osteoporosis) were treated with vitamin K2 or with a combination of vitamin K2 and vitamin D3. Seventeen women received daily oral administration of 45 mg vitamin K2 and 17 women received daily oral administration of 45 mg vitamin K2 plus 0.75 microg 1alpha-hydroxyvitamin D3. Serum levels of uc OC, intact osteocalcin (OC) and bone alkaline phosphatase (BAP), urinary deoxypyridinoline (DPD) levels and BMD at the lumbar spine were measured before and at 1 and 2 years after the start of treatment.
  
  
  RESULTS
  Serum uc OC levels in women treated with vitamin K2 alone and with both vitamin K2 and vitamin D3 decreased significantly (p < 0.05). Serum levels of intact OC and BAP in women treated with vitamin K2 did not show significant changes, while those in women who received the combined treatment decreased significantly (p < 0.05). On the other hand, urinary DPD level in women treated with vitamin K2 did not change, while that in women who received the combined treatment tended to decrease (p < 0.1).
  
  
  CONCLUSIONS
  Serum uc OC levels in early postmenopausal women who received vitamin K2 decreased due to carboxylation of uc OC. Combined treatment with vitamin K2 and vitamin D3 may be effective for sustaining BMD in early postmenopausal women whose bone turnovers are highly activated.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine, University of Tokushima, Tokushima, Japan. yasui@clin.med.tokushima-u.ac.jp
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yasui
authors.forename: Yuka
authors.initials: Y
authors.lastname: Miyatani
authors.forename: Junko
authors.initials: J
authors.lastname: Tomita
authors.forename: Masayo
authors.initials: M
authors.lastname: Yamada
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Uemura
authors.forename: Masakazu
authors.initials: M
authors.lastname: Miura
authors.forename: Minoru
authors.initials: M
authors.lastname: Irahara
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D000596:Amino Acids / Q000652:urine; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D001851:Bone Diseases, Metabolic / Q000097:blood / Q000188:drug therapy / Q000378:metabolism / Q000652:urine; D002762:Cholecalciferol / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood / Q000378:metabolism*; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism / Q000652:urine; D017698:Postmenopause / Q000097:blood / Q000187:drug effects* / Q000378:metabolism / Q000652:urine; D024482:Vitamin K 2 / Q000627:therapeutic use*
chemical_list: D000596:Amino Acids; D050071:Bone Density Conservation Agents; D015675:Osteocalcin; D024482:Vitamin K 2; D002762:Cholecalciferol; C036020:deoxypyridinoline; D000469:Alkaline Phosphatase