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 .
A longitudinal study of the effect of vitamin K2 on bone mineral density in postmenopausal women a comparative study with vitamin D3 and estrogen-progestin therapy.
OBJECTIVES To investigate the effect of vitamin K2 treatment for a year on spinal bone mineral density ( BMD ) in postmenopausal women , comparing with vitamin D3 hormone replacement therapy and to determine the factors which affect the efficacy of vitamin K2 therapy . SUBJECTS AND METHODS Seventy-two postmenopausal women were r and omized into four groups and treated with respective agents . Before the therapy , 6 and 12 months after the treatment , their lumbar spine BMD were measured by dual energy X-ray absorptiometry . The rates of change in BMD ( delta BMD ) were calculated . Correlations of BMD with age , year since menopause and the initial BMD were determined . RESULTS Vitamin K2 suppressed the decrease in spinal BMD as compared with no treatment group . BMD in women treated with vitamin K2 was inversely correlated with their age ( r = -0.54 ; P < 0.05 ) . CONCLUSIONS Vitamin K2 therapy may be a useful method for preventing postmenopausal spinal bone mineral loss . In addition , the therapy should be started early in postmenopausal period
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 .