In the current study, vitamin K intake adequacy, but not continuous vitamin K intake level, is robustly associated with mortality, which supports the possibility, that vitamin K intake may not be linearly associated with mortality but it may have a threshold effect. Therefore, achieving adequate vitamin K intake may be important in CKD patients. Despite the robust association of adequate vitamin K intake with mortality, a cautious interpretation is warranted because vitamin K could be a marker of a healthier dietary pattern. Moreover, food sources of vitamin K such as green vegetables contain a lot of other healthy dietary factors, such as dietary fibers, which has been shown to be associated with reduced mortality.23 The HR was attenuated when dietary fiber was adjusted for in model 3 (Table 2), which could be due to potential residual confounding effect of healthy dietary pattern.