title: Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled Trials.
abstract: Vitamin K is essential for bone health, but the effects of low-dose vitamin K intake in Japanese subjects remain unclear. We investigated the effective minimum daily menaquinone-7 dose for improving osteocalcin γ-carboxylation. Study 1 was a double-blind, randomized controlled dose-finding trial; 60 postmenopausal women aged 50-69 y were allocated to one of four dosage group and consumed 0, 50, 100, or 200 μg menaquinone-7 daily for 4 wk, respectively, with a controlled diet in accordance with recommended daily intakes for 2010 in Japan. Study 2 was a double-blind, randomized placebo-controlled trial based on the results of Study 1; 120 subjects aged 20-69 y were allocated to the placebo or MK-7 group and consumed 0 or 100 μg menaquinone-7 daily for 12 wk, respectively. In both studies, circulating carboxylated osteocalcin and undercarboxylated osteocalcin were measured. The carboxylated osteocalcin/undercarboxylated osteocalcin ratio decreased significantly from baseline in the 0 μg menaquinone-7 group, in which subjects consumed the recommended daily intake of vitamin K with vitamin K1 and menaquinone-4 (Study 1). Menaquinone-7 increased the carboxylated osteocalcin/undercarboxylated osteocalcin ratio dose dependently, and significant effects were observed in both the 100 and 200 μg groups compared with the 0 μg group. Undercarboxylated osteocalcin concentrations decreased significantly, and the carboxylated osteocalcin/undercarboxylated osteocalcin ratio increased significantly in the 100 μg menaquinone-7 group compared with the placebo group (Study 2). Daily menaquinone-7 intake ≥100 μg was suggested to improve osteocalcin γ-carboxylation.
authors.affiliation: R&D Division, J-Oil Mills, Inc.
authors.forename: Naoko
authors.initials: N
authors.lastname: Inaba
authors.forename: Toshiro
authors.initials: T
authors.lastname: Sato
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D001842:Bone and Bones; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood*; D010024:Osteoporosis / Q000097:blood* / Q000517:prevention & control; D024482:Vitamin K 2 / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D014815:Vitamins / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D014815:Vitamins; D015675:Osteocalcin; D024482:Vitamin K 2; C062629:menaquinone 7