Associations of serum vitamin C concentrations with risk of all-cause and cause-specific mortality among individuals with and without type 2 diabetes.

Higher serum vitamin C concentrations were significantly associated with lower risk of mortality in participants with T2D in a linear dose-response manner, while a nonlinear association was observed in participants without T2D, with an apparent threshold around 48.0 μmol/L. These findings suggest that the optimal vitamin C requirement may differ in individuals with and without T2D.