Conclusions and Relevance In this systematic review and meta- analysis , neither intermittent nor daily dosing with st and ard doses of vitamin D alone was associated with reduced risk of fracture , but daily supplementation with both vitamin D and calcium was a more promising strategy
Importance Vitamin D and calcium supplements are recommended for the prevention of fracture , but previous r and omized clinical trials ( RCTs ) have reported conflicting results , with uncertainty about optimal doses and regimens for supplementation and their overall effectiveness .
Objective To assess the risks of fracture associated with differences in concentrations of 25-hydroxyvitamin D ( 25[OH]D ) in observational studies and the risks of fracture associated with supplementation with vitamin D alone or in combination with calcium in RCTs .
Two-year randomized controlled trial of vitamin K1 (phylloquinone) and vitamin D3 plus calcium on the bone health of older women.
UNLABELLED Dietary supplementation with vitamin K(1 ) , with vitamin D(3 ) and calcium or their combination , was examined in healthy older women during a 2-year , double-blind , placebo-controlled trial . Combined vitamin K with vitamin D plus calcium was associated with a modest but significant increase in BMC at the ultradistal radius but not at other sites in the hip or radius . INTRODUCTION The putative beneficial role of high dietary vitamin K(1 ) ( phylloquinone ) on BMD and the possibility of interactive benefits with vitamin D were studied in a 2-year double-blind , placebo-controlled trial in healthy Scottish women > or = 60 years of age . MATERIAL S AND METHODS Healthy , nonosteoporotic women ( n = 244 ) were r and omized to receive either ( 1 ) placebo , ( 2 ) 200 microg/day vitamin K(1 ) , ( 3 ) 10 microg ( 400 IU ) vitamin D(3 ) plus 1000 mg calcium/day , or ( 4 ) combined vitamins K(1 ) and D(3 ) plus calcium . Baseline and 6-month measurements included DXA bone mineral scans of the hip and wrist , markers of bone turnover , and vitamin status . Supplementation effects were tested using multivariate general linear modeling , with full adjustment for baseline and potential confounding variables . RESULTS Significant bone mineral loss was seen only at the mid-distal radius but with no significant difference between groups . However , women who took combined vitamin K and vitamin D plus calcium showed a significant and sustained increase in both BMD and BMC at the site of the ultradistal radius . Serum status indicators responded significantly to respective supplementation with vitamins K and D. Over 2 years , serum vitamin K(1 ) increased by 157 % ( p < 0.001 ) , the percentage of undercarboxylated osteocalcin ( % GluOC ) decreased by 51 % ( p < 0.001 ) , serum 25-hydroxyvitamin D [ 25(OH)D ] increased by 17 % ( p < 0.001 ) , and PTH decreased by 11 % ( p = 0.049 ) . CONCLUSIONS These results provide evidence of a modest synergy in healthy older women from nutritionally relevant intakes of vitamin K(1 ) together with supplements of calcium plus moderate vitamin D(3 ) to enhance BMC at the ultradistal radius , a site consisting of principally trabecular bone . The substantial increase in gamma-carboxylation of osteocalcin by vitamin K may have long-term benefits and is potentially achievable by increased dietary intakes of vitamin K rather than by supplementation
Conclusions and Relevance In this systematic review and meta- analysis , neither intermittent nor daily dosing with st and ard doses of vitamin D alone was associated with reduced risk of fracture , but daily supplementation with both vitamin D and calcium was a more promising strategy
Importance Vitamin D and calcium supplements are recommended for the prevention of fracture , but previous r and omized clinical trials ( RCTs ) have reported conflicting results , with uncertainty about optimal doses and regimens for supplementation and their overall effectiveness .
Objective To assess the risks of fracture associated with differences in concentrations of 25-hydroxyvitamin D ( 25[OH]D ) in observational studies and the risks of fracture associated with supplementation with vitamin D alone or in combination with calcium in RCTs .