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 .
Effects of risedronate alone or combined with vitamin K2 on serum undercarboxylated osteocalcin and osteocalcin levels in postmenopausal osteoporosis
Risedronate decreases osteoporotic fracture incidence ; however , its effects remain unclear in elderly osteoporotic patients . Vitamin K mediates carboxylation of osteocalcin ( OC ) , and high undercarboxylated osteocalcin ( ucOC ) levels indicate vitamin K deficiency and increased osteoporotic fracture risk . We aim ed to evaluate the effects of risedronate alone or combined with vitamin K2 on serum ucOC , OC , and incidence of vertebral fractures in elderly osteoporotic patients . A total of 101 women with postmenopausal osteoporosis aged > 60 years were r and omly stratified into two groups — R group ( n = 51 ) , treated with risedronate alone ; and R + K group ( n = 50 ) , treated with risedronate and vitamin K2 .  Serum ucOC , OC and incidence of vertebral fractures were evaluated before treatment and at 6 and 12 months post-treatment . Decreased ucOC rates at 6 and 12 months were not significant between groups . However , at 6 and 12 months , decreased OC rates in the R group ( p < 0.01 and 0.05 , respectively ) were significantly higher than in the R + K group , and ucOC/OC change rates in the R group ( p < 0.05 and 0.001 , respectively ) were significantly lower than in the R + K group . Vertebral fracture incidence was not significantly different between the groups at 6 and 12 months . ucOC levels in patients with incident vertebral fractures were significantly higher than in patients without incident vertebral fractures in the R group at 6 months ( p < 0.05 ) . Although no significant difference was observed for ucOC decrease rate and incidence of vertebral fractures between treatments , ucOC levels in patients with incident vertebral fractures were significantly greater than in patients without when using risedronate alone
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 .