What is the optimal level of vitamin D in non-dialysis chronic kidney disease population?

Table 3 Adjusted Cox proportional hazards models of patient survival (events = 46)

Model	Covariates controlled for	Adjusted HR (95%CI)	P
0 (Unadjusted)	25-hydroxivitamin D levels (mg/dL)	0.95 (0.91-0.99)	0.009
1	25-hydroxivitamin D levels (mg/dL) + age	0.95 (0.91-0.99)	0.009
2	Model 1 + diabetes mellitus, ischemic heart disease, chronic heart failure	0.96 (0.92-0.99)	0.028
3	Model 1 + peripheral arterial disease, abnormal ABPI1, phosphorous (mg/dL)	0.95 (0.92-0.99)	0.023
4	Model 1 + DBP (mm Hg), 1,25(OH)2 vitamin D (pg/mL), estimated GFR (mL/min per 1.73 m2)	0.96 (0.92-0.99)	0.020
5	Model 1 + vascular calcification [Kauppila score (log), Adragao score (log)], CKD stage 5	0.95 (0.91-1.00)	0.050
6	Model 1 + obesity, hemoglobin (g/L), albumin (g/dL)	0.95 (0.92-0.99)	0.019

¹< 0.9 or >1.3. ABPI: Ankle-brachial pressure index; DBP: Diastolic blood pressure; GFR: Glomerular filtration rate.