This systematic review suggests that supplementation with phytonadione and menaquinone-4 reduces bone loss .
In the case of the latter , there is a strong effect on incident fractures among Japanese patients
BACKGROUND Observational and some experimental data suggest that low intake of vitamin K may be associated with an increased risk of fracture .
OBJECTIVE To assess whether oral vitamin K ( phytonadione and menaquinone ) supplementation can reduce  bone loss  and prevent fractures .
Vitamin K2 (menatetrenone) effectively prevents fractures and sustains lumbar bone mineral density in osteoporosis.
We attempted to investigate whether vitamin K2 ( menatetrenone ) treatment effectively prevents the incidence of new fractures in osteoporosis . A total of 241 osteoporotic patients were enrolled in a 24-month r and omized open label study . The control group ( without treatment ; n = 121 ) and the vitamin K2-treated group ( n = 120 ) , which received 45 mg/day orally vitamin K2 , were followed for lumbar bone mineral density ( LBMD ; measured by dual-energy X-ray absorptiometry [ DXA ] ) and occurrence of new clinical fractures . Serum level of Glu-osteocalcin ( Glu-OC ) and menaquinone-4 levels were measured at the end of the follow-up period . Serum level of OC and urinary excretion of deoxypyridinoline ( DPD ) were measured before and after the treatment . The background data of these two groups were identical . The incidence of clinical fractures during the 2 years of treatment in the control was higher than the vitamin K2-treated group ( chi2 = 10.935 ; p = 0.0273 ) . The percentages of change from the initial value of LBMD at 6 , 12 , and 24 months after the initiation of the study were -1.8 + /- 0.6 % , -2.4 + /- 0.7 % , and -3.3 + /- 0.8 % for the control group , and 1.4 + /- 0.7 % , -0.1 + /- 0.6 % , and -0.5 + /- 1.0 % for the vitamin K2-treated group , respectively . The changes in LBMD at each time point were significantly different between the control and the treated group ( p = 0.0010 for 6 months , p = 0.0153 for 12 months , and p = 0.0339 for 24 months ) . The serum levels of Glu-OC at the end of the observation period in the control and the treated group were 3.0 + /- 0.3 ng/ml and 1.6 + /- 0.1 ng/ml , respectively ( p < 0.0001 ) , while the serum level of OC measured by the conventional radioimmunoassay ( RIA ) showed a significant rise ( 42.4 + /-6.9 % from the basal value ) in the treated group at 24 months ( 18.2 + /- 6.1 % for the controls;p = 0.0081 ) . There was no significant change in urinary DPD excretion in the treated group . These findings suggest that vitamin K2 treatment effectively prevents the occurrence of new fractures , although the vitamin K2-treated group failed to increase in LBMD . Furthermore , vitamin K2 treatment enhances gamma-carboxylation of the OC molecule
This systematic review suggests that supplementation with phytonadione and menaquinone-4 reduces bone loss .
In the case of the latter , there is a strong effect on incident fractures among Japanese patients
BACKGROUND Observational and some experimental data suggest that low intake of vitamin K may be associated with an increased risk of fracture .
OBJECTIVE To assess whether oral vitamin K ( phytonadione and menaquinone ) supplementation can reduce  bone loss  and prevent fractures .