Sensitivity analysis showed that overall estimates were not affected by elimination of any study .
We did not observe any evidence regarding publication bias .
In conclusion , vitamin K supplementation had no signiﬁcant effect on glycemic control in healthy subjects .
Type 2 diabetes mellitus ( T2DM ) is one of the most important public health issues .
Vitamin K supplementation might have favorable effect on risk factors of T2DM .
The aim of this study was to perform a systematic review and meta- analysis of interventional studies to examine the effect of vitamin K supplementation on glycemic indices .
Vitamin K2 Prevents Hyperglycemia and Cancellous Osteopenia in Rats with Streptozotocin-Induced Type 1 Diabetes
The purpose of the present study was to examine the effect of vitamin K2 on cancellous and cortical bone mass in rats with streptozotocin (STZ)-induced type 1 diabetes . Twenty-seven male Sprague-Dawley rats aged 12 weeks were r and omized by the weight-stratified method into the following three groups : age-matched control group , STZ + vehicle group , and STZ + vitamin K2 group . STZ ( 40 + 50 mg/kg ) was administered intravenously twice during the initial 1-week period . Vitamin K2 ( menatetrenone , 30 mg/kg ) was administered orally 5 days a week . After 12 weeks of treatment , the serum glucose concentration and femoral length and weight were measured and histomorphometric analysis was performed on the cancellous and cortical bone of the distal femoral metaphysis and femoral diaphysis , respectively . STZ administration induced hyperglycemia and a decrease in femoral weight . The STZ + vehicle group also showed cancellous osteopenia due to a decrease in the number of osteoblasts/bone surface ( N.Ob/BS ) and the osteoblast surface (ObS)/BS without any significant changes in bone-resorption parameters , but it did not have a significant decrease in cortical bone mass . Administration of vitamin K2 to STZ-treated rats prevented the development of hyperglycemia and a decrease in femoral weight .  Vitamin K2 also prevented cancellous osteopenia by inhibiting the decrease in N.Ob/BS and ObS/BS without significantly affecting bone-resorption parameters , but it did not significantly increase cortical bone mass . These results suggest that vitamin K2 has beneficial effects on glucose concentration and cancellous bone mass in rats with STZ-induced type 1 diabetes
Sensitivity analysis showed that overall estimates were not affected by elimination of any study .
We did not observe any evidence regarding publication bias .
In conclusion , vitamin K supplementation had no signiﬁcant effect on glycemic control in healthy subjects .
Type 2 diabetes mellitus ( T2DM ) is one of the most important public health issues .
Vitamin K supplementation might have favorable effect on risk factors of T2DM .
The aim of this study was to perform a systematic review and meta- analysis of interventional studies to examine the effect of vitamin K supplementation on glycemic indices .