The prevalence of vitamin D deficiency in pre-dialysis patients with chronic kidney disease

Abstract

Introduction: Reduced Vitamin D levels were seen early in the course of chronic kidney disease (CKD). Its prevalence increased and severity worsened with the progression of CKD. Aim: To assess the prevalence of Vitamin D deficiency in pre-dialysis CKD patients. Material and methods: In the study 100 adult patients were divided into three groups depending on estimated glomerular filtration rate (EGFR). Group A consisted of 30 patients with EGFR between 30-49 ml/min, group B consisted of 33 patients with EGFR between 15-29 ml/min, and group C had 37 patients with EGFR less than 15 ml/min. Renal functions, intact parathyroid hormone, 25 hydroxy Vitamin D, and 1,25 dihydroxy Vitamin D were measured at baseline. Results: The mean serum phosphate and iPTH levels increased steadily as CKD progressed. On the other hand, mean corrected serum calcium levels, 25 hydroxy Vitamin D, and 1,25 dihydroxy Vitamin D decreased progressively in group A, B, and C. There was a significant increase in mean serum iPTH level from group A to group C (p < 0.05). The mean level of 25 hydroxy Vitamin D and 1,25 dihydroxy Vitamin D showed a trend of declination from group A to C (p < 0.05). Both 25 hydroxy Vitamin D and 1,25 dihydroxy Vitamin D positively correlated with EGFR. There was negative correlation of 25 hydroxy Vitamin D and 1,25 dihydroxy Vitamin D with iPTH and proteinuria. Conclusions: The study concluded that both prevalence and severity of low 25 hydroxy and 1,25 dihydroxy Vitamin D increases with progression of CKD. Their levels were negatively correlated to factors like parathyroid hormone levels and proteinuria.