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 .
Randomized controlled study on the prevention of osteoporotic fractures (OF study): a phase IV clinical study of 15-mg menatetrenone capsules
An open-label study with blinded evaluation was performed to compare the preventive effect of a calcium supplement alone ( monotherapy ) or calcium supplement plus menatetrenone ( combined therapy ) on fracture in osteoporotic postmenopausal women aged 50 years or older . Patients were r and omized to receive monotherapy ( n = 2,193 ) or combined therapy ( n = 2,185 ) . Before r and omization , the subjects were stratified into a subgroup without vertebral fractures ( n = 2,986 ; no-fracture subgroup ) and a subgroup with at least one vertebral fracture ( n = 1,392 ; fracture subgroup ) . The incidence rate of new vertebral fractures during 36 months of treatment ( primary endpoint ) did not differ significantly between either subgroup of the two treatment groups . Although the cumulative 48-month incidence rate of new clinical fractures ( secondary endpoint ) was lower in the combined therapy group , the difference was not significant . There was a lower risk of new vertebral fractures in patients with at least five baseline fractures who received combined therapy . Also , the loss of height was less with combined therapy than with monotherapy  among patients 75 years of age or older at enrollment , those whose last menstrual period occurred 30 years or more before enrollment , and those with at least five vertebral fractures at enrollment .  Adverse events and adverse reactions were more frequent in the combined therapy group . In conclusion , menatetrenone therapy was not effective for preventing vertebral fractures in the full analysis set of this study , but the results suggested that it may prevent vertebral fractures in patients with more advanced osteoporosis
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 .