Prognostic significance of 25‐hydroxivitamin D entirely explained by a higher comorbidity burden: Experience from a S outh‐ E astern E uropean D ialysis C ohort

Vitamin D deficiency is still a common problem particularly in the elderly and in individuals with various degrees of renal impairment. The present study aimed to evaluate the association between plasma concentrations of 25( OH ) D and death in a large cohort of prevalent patients on hemodialysis ( HD ) from south‐east R omania, a typical B alkan region. This is an observational prospective study that included a total of 570 patients on maintenance HD . Study patients were classified into three groups by baseline 25( OH ) D levels: (1) sufficient 25( OH ) D —i.e., >30 ng/mL; (2) insufficient 25( OH ) D —i.e., between 10 and 29 ng/mL; and (3) deficient 25( OH ) D —i.e., <10 ng/mL. During the follow‐up period of 14 months, 68 patients (11.9%) died, the K aplan– M eier analysis showing significant differences in all‐cause mortality for chronic kidney disease patients in different 25( OH ) D groups ( P  = 0.002). Unadjusted C ox regression analysis also showed significant differences in survival. The multivariate C ox regression model showed no significant differences in survival according to vitamin D levels. Hazard ratio for death in the “<10 ng/mL” group was 1.619 ( P  = 0.190) and in the “10–30 ng/mL” group was 0.837 ( P  = 0.609). In our dialysis population with a high comorbidity burden, low 25( OH )D concentration was not associated with mortality in the adjusted C ox model, suggesting that vitamin D deficiency could represent only a non‐specific marker for a poor health status, with less impact on mortality.