title: Low-dose menaquinone-4 improves γ-carboxylation of osteocalcin in young males: a non-placebo-controlled dose-response study.
abstract: BACKGROUND
  Menaquinone-4 is a type of vitamin K that has a physiological function in maintaining bone quality via γ-carboxylation of osteocalcin. However, little is known about the beneficial effect of intake of dosages below1500 μg/day.
  
  
  RESULTS
  Fifteen healthy males aged 25.0 years (median) participated in a non-placebo-controlled dose-examination study. They received menaquinone-4 daily for 5 weeks at 0, 300, 600, 900, and 1500 μg/day in weeks 1, 2, 3, 4, and 5, respectively. Compared with baseline, serum γ-carboxylated osteocalcin levels were significantly greater at an intake of 900 μg/day or more; serum undercarboxylated osteocalcin levels and the ratio of serum undercarboxylated osteocalcin to γ-carboxylated osteocalcin were significantly lower than baseline at doses of 600 μg/day or more.
  
  
  CONCLUSIONS
  This preliminary graded-dose study suggested that menaquinone-4 supplementation at 600 μg/day or more is likely to be important in terms of vitamin K requirements for bone health.
authors.forename: Eriko
authors.initials: E
authors.lastname: Nakamura
authors.forename: Mami
authors.initials: M
authors.lastname: Aoki
authors.forename: Fumiko
authors.initials: F
authors.lastname: Watanabe
authors.affiliation: Healthcare Products Development Center, KYOWA HAKKO BIO CO,, LTD, 2 Miyukigaoka, Tsukuba, Ibaraki 305-0841, Japan. ayako.kamimura@kyowa-kirin.co.jp.
authors.forename: Ayako
authors.initials: A
authors.lastname: Kamimura
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D001835:Body Weight; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D015675:Osteocalcin / Q000097:blood*; D010837:Vitamin K 1 / Q000097:blood; D024482:Vitamin K 2 / Q000008:administration & dosage / Q000031:analogs & derivatives*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D015675:Osteocalcin; D024482:Vitamin K 2; C030814:menatetrenone; D010837:Vitamin K 1