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 .
Toenail Selenium and Incidence of Type 2 Diabetes in U.S. Men and Women
OBJECTIVE Compelling biological pathways suggest that selenium ( Se ) may lower onset of type 2 diabetes mellitus ( T2DM )  , but very few studies have evaluated this relationship , with mixed results . We examined the association between toenail Se and incidence of T2DM . RESEARCH DESIGN AND METHODS We performed prospect i ve analyses in two separate U.S. cohorts , including 3,630 women and 3,535 men , who were free of prevalent T2DM and heart disease at baseline in 1982–1983 and 1986–1987 , respectively .  Toenail Se concentration was quantified using neutron activation analysis , and diabetes cases were identified by biennial question naires and confirmed by a detailed supplementary question naire . Hazard ratios of incident T2DM according to Se levels were calculated using Cox proportional hazards . RESULTS During 142,550 person-years of follow-up through 2008 , 780 cases of incident T2DM occurred . After multivariable adjustment , the risk of T2DM was lower across increasing quintiles of Se , with pooled relative risks across the two cohorts of 1.0 ( reference ) , 0.91 ( 95 % CI 0.73–1.14 ) , 0.78 ( 0.62–0.99 ) , 0.72 ( 0.57–0.91 ) , and 0.76 ( 0.60–0.97 ) , respectively ( P for trend = 0.01 ) . Results were similar excluding the few individuals ( 4 % ) who used Se supplements . In semiparametric analyses , the inverse relationship between Se levels and T2DM risk appeared to be linear . CONCLUSIONS At dietary levels of intake , individuals with higher toenail Se levels are at lower risk for T2DM . Further research is required to determine whether varying results in this study versus prior trials relate to differences in dose , source , statistical power , residual confounding factors , or underlying population risk
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 .