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

摘要

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.