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 .
Phylloquinone supplementation improves glycemic status independent of the effects of adiponectin levels in premonopause women with prediabetes: a double-blind randomized controlled clinical trial
Background Vitamin K , as a cofactor in the gamma carboxylation of certain glutamic acid ( Gla ) residues , has been related to glucose metabolism and insulin sensitivity . Osteocalcin , also known as bone γ-carboxyglutamic acid , increases β-cell proliferation as well as insulin and adiponectin secretion , which improve glucose tolerance and insulin sensitivity . Thus , the purpose of the present study was to examine the possible role of adiponectin as a mediator of glucose homeostasis following phylloquinone supplementation in premonopause women with prediabetes . Methods Eighty two women were r and omized to consume vitamin k1 supplement ( n = 39 ) or placebo ( n = 43 ) for four weeks . Participants in vitamin K1 treatment group received one pearl softgel capsule containing 1000 micrograms phylloquinone while the placebo group received one placebo capsules daily for four weeks . The Blood sample s were collected at baseline and after a four-week intervention to quantify osteocalcin , adiponectin , leptin and relevant variables . Results Phylloquinone supplementation significantly increased serum adiponectin concentration ( 1.24 ± 1.90 compared with −0.27 ± 1.08 μg/ml ) , and did not alter total osteocalcin ( 0.50 ± 4.11 compared with 0.13 ± 1.85 ng/ml ) and leptin ( −0.29 ± 8.23 compared with −1.15 ± 5.25 ng/ml ) compared with placebo . Adjustments for total osteocalcin and adiponectin using analysis of covariance ( ANCOVA ) did not affect the association of glycemic status with related variables . Conclusions In conclusion our study demonstrated that phylloquinone supplementation  improved glycemic status in premonopausal prediabetic women independent of adiponectin . Trial registration This trial was registered in Iranian Registry of Clinical Trials with ID number of I RCT 2013120915724N1
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 .