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 .
Use of vitamin K2 (menatetrenone) and 1,25-dihydroxyvitamin D3 in the prevention of bone loss induced by leuprolide.
The purpose of this study is to evaluate the efficacy of vitamin K2 and 1,25-dihydroxyvitamin D3 [ 1,25-(OH)2D3 ] in preventing bone loss induced by estrogen deficiency during therapy with the GnRH agonist ( GnRH-a ) leuprolide .  One hundred ten women ( mean age , 46.2+/-0.5 yr ) , receiving leuprolide therapy for estrogen-dependent diseases ( such as endometriosis and uterine leiomyomas ) , were r and omly allocated into four groups ( group A , leuprolide only ; group B , leuprolide with vitamin K2 ; group C , leuprolide with 1,25-(OH)2D3 ; and group D , leuprolide with vitamin K2 and 1,25-(OH)2D3 ) .  Bone mineral density of the lumbar spine was measured by dual-energy x-ray absorptiometry before and after 6 months of treatment . Bone formation and resorption markers were also measured before and after 6 months of treatment . There were no significant differences in the background parameters among the four groups . Bone mineral density was reduced in all four groups , but the percent changes varied slightly , at - 5.25 % ( group A ) , -3.72 % ( P < 0.05 vs. group A ) ( group B ) , -4.13 % ( group C ) , and -3.59 % ( P < 0.01 vs. group A ) ( group D ) , respectively . Bone formation markers were significantly increased in all four groups , and the percent changes of bone formation markers were highest in group B. Bone resorption markers also increased significantly in all four groups after treatment of 6 months . Group B tended to have the highest percent changes of bone resorption markers among the four groups , but these increases were not significantly different between any of the groups . Vitamin K2 , especially when combined with 1,25-(OH)2D3 , can partially prevent bone loss caused by estrogen deficiency . However , because this effect is attributable mainly to the activation of bone formation , it is not sufficient to eliminate bone loss induced by GnRH-a therapy
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 .