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 K intake and hip fractures in women: a prospective study.
BACKGROUND Vitamin K mediates the gamma-carboxylation of glutamyl residues on several bone proteins , notably osteocalcin . High serum concentrations of undercarboxylated osteocalcin and low serum concentrations of vitamin K are associated with lower bone mineral density and increased risk of hip fracture . However , data are limited on the effects of dietary vitamin K. OBJECTIVE We investigated the hypothesis that high intakes of vitamin K are associated with a lower  risk of hip fracture in women . DESIGN We conducted a prospect i ve analysis within the Nurses ' Health Study cohort . Diet was assessed in 72327 women aged 38 - 63 y with a food-frequency question naire in 1984 ( baseline ) . During the subsequent 10 y of follow-up , 270 hip fractures result ing from low or moderate trauma were reported . RESULTS Women in quintiles 2 - 5 of vitamin K intake had a significantly lower age-adjusted relative risk ( RR : 0.70 ; 95 % CI : 0.53 , 0.93 ) of hip fracture than women in the lowest quintile ( < 109 microg/d ) . Risk did not decrease between quintiles 2 and 5 and risk estimates were not altered when other risk factors for osteoporosis , including calcium and vitamin D intakes , were added to the models . Risk of hip fracture was also inversely associated with lettuce consumption ( RR : 0.55 ; 95 % CI : 0.40 , 0.78 ) for one or more servings per day compared with one or fewer servings per week ) , the food that contributed the most to dietary vitamin K intakes . CONCLUSIONS Low intakes of vitamin K may increase the  risk of hip fracture in women . The data support the suggestion for a re assessment of the vitamin K requirements that are based on bone health and blood coagulation
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 .