Summary Vitamin K may affect  bone mineral density and fracture incidence .
Since publication of a previous systematic review the integrity of some of the previous evidence has been question ed and further trials have been published .
Introduction This systematic review was design ed to assess the effectiveness of oral vitamin K supplementation for increasing bone mineral density  and reducing fractures in adults .
Effect of vitamin K supplementation on bone loss in elderly men and women.
CONTEXT Vitamin K has been implicated in bone health , primarily in observational studies . However , little is known about the role of phylloquinone supplementation on prevention of bone loss in men and women . OBJECTIVE The objective of this study was to determine the effect of 3-yr phylloquinone supplementation on change in bone mineral density ( BMD ) of the femoral neck bone in older men and women who were calcium and vitamin D replete . DESIGN , PARTICIPANTS , AND INTERVENTION In this 3-yr , double-blind , controlled trial , 452 men and women ( 60 - 80 yr ) were r and omized equally to receive a multivitamin that contained either 500 mug/d or no phylloquinone plus a daily calcium ( 600 mg elemental calcium ) and vitamin D ( 400 IU ) supplement . MAIN OUTCOME MEASURES Measurements of the femoral neck , spine ( L2-L4 ) , and total-body BMD , bone turnover , and vitamins K and D status were measured every 6 - 12 months . Intent-to-treat analysis was used to compare change in measures in 401 participants who completed the trial . RESULTS There were no differences in changes in BMD measurements at any of the anatomical sites measured between the two groups . The group that received the phylloquinone supplement had significantly higher phylloquinone and significantly lower percent undercarboxylated osteocalcin concentrations compared with the group that did not receive phylloquinone . No other biochemical measures differed between the two groups . CONCLUSIONS Phylloquinone supplementation in a dose attainable in the diet does not confer any additional benefit for bone health at the spine or hip when taken with recommended amounts of calcium and vitamin
Summary Vitamin K may affect  bone mineral density and fracture incidence .
Since publication of a previous systematic review the integrity of some of the previous evidence has been question ed and further trials have been published .
Introduction This systematic review was design ed to assess the effectiveness of oral vitamin K supplementation for increasing bone mineral density  and reducing fractures in adults .