Fig. 1

Multivariable restricted cubic spline analyses of incident events according to serum 25-hydroxyvitamin D level among in prediabetic participants. HR hazard ratio, CI confidence interval. *HRs were adjusted for sex (female/male), age (continuous), ethnicity (Whites/non-Whites), income (< £18,000/£18,000–30,999/£31,000–51,999/£52,000–100,000/ > £100,000), smoking and drinking habits (never/former/current), BMI (continuous), systolic BP (continuous), total cholesterol (continuous), high-density lipoprotein (continuous), serum creatinine (continuous), and the use of vitamin D supplement (yes/no), antihypertensive drugs (yes/no), lipid-regulating drugs (yes/no), and statins (yes/no). †P-values of non-linear were 0.013 for myocardial infarction, 0.005 for stroke, 0.281 for diabetic nephropathy, and 0.208 for diabetic retinopathy