Low-dose vitamin K2 (MK-4) supplementation for 12 months improves bone metabolism and prevents forearm bone loss in postmenopausal Japanese women

• DOI: 10.1007/s00774-013-0472-7
• Publication Date: 2013-05-23T00:41:56Z
• Authors: Noriko Koitaya; Mariko Sekiguchi; Yuko Tousen; Yoriko Nishide; Akemi Morita; Jun Yamauchi; Yuko Gando; Motohiko Miyachi; Mami Aoki; Miho Komatsu; Fumiko Watanabe; Koji Morishita; Yoshiko Ishimi
• Keywords: Time Factors; Vitamin K 2; Middle Aged; 3. Good health; Postmenopause; Forearm; 03 medical and health sciences; 0302 clinical medicine; Double-Blind Method; Japan; Bone Density; Surveys and Questionnaires; Dietary Supplements; Humans; Female; Biomarkers; Chromatography, High Pressure Liquid; Osteoporosis, Postmenopausal; Aged

Menaquinone-4 (MK-4) administered at a pharmacological dosage of 45 mg/day has been used for the treatment of osteoporosis in Japan. However, it is not known whether a lower dose of MK-4 supplementation is beneficial for bone health in healthy postmenopausal women. The aim of this study was to examine the long-term effects of 1.5-mg daily supplementation of MK-4 on the various markers of bone turnover and bone mineral density (BMD). The study was performed as a randomized, double-blind, placebo-controlled trial. The participants (aged 50-65 years) were randomly assigned to one of two groups according to the MK-4 dose received: the placebo-control group (n = 24) and the 1.5-mg MK-4 group (n = 24). The baseline concentrations of undercarboxylated osteocalcin (ucOC) were high in both groups (>5.1 ng/ml). After 6 and 12 months, the serum ucOC concentrations were significantly lower in the MK-4 group than in the control group. In the control group, there was no significant change in serum pentosidine concentrations. However, in the MK-4 group, the concentration of pentosidine at 6 and 12 months was significantly lower than that at baseline. The forearm BMD was significantly lower after 12 months than at 6 months in the control group. However, there was no significant decrease in BMD in the MK-4 group during the study period. These results suggest that low-dose MK-4 supplementation for 6-12 months improved bone quality in the postmenopausal Japanese women by decreasing the serum ucOC and pentosidine concentrations, without any substantial adverse effects.