Vitamin D Levels among Chronic Kidney Disease Patients at a Tertiary Care Hospital: A Cross-sectional Study

Introduction: In patients with Chronic Kidney Disease (CKD), a high prevalence of metabolite abnormalities has been observed. Numerous studies have demonstrated that individuals with reduced Glomerular Filtration Rate (GFR) are more susceptible to severe vitamin D deficiency compared to those with normal kidney function. Aim: To investigate the association between vitamin D levels and the severity of CKD among patients at Siddhartha Medical College, GGH in Vijayawada, Andhra Pradesh, India. Materials and Methods: The present hospital-based cross-sectional study was conducted at Siddhartha Medical College, GGH, Vijayawada, Andhra Pradesh, India from December 2021 to February 2022. A total of 100 CKD patients with a GFR of less than 60 mL/min/1.72 m2 were included in the study. Vitamin D levels were assessed using Chemiluminescence immunoassay (Access 2, Beckman Coulter), and vitamin D deficiency was defined as 25-OH vitamin D levels of less than 10 ng/mL, while insufficiency was defined as levels between 10 to 30 ng/mL. Statistical analysis was performed using Analysis of Variance (ANOVA) test and Pearson’s correlation test. Results: The mean age of the study population was 53.25±7.6 years, with the majority (32%) belonging to the 51-60 years age group. In terms of gender distribution, approximately three-fourths (72%) of the subjects were male. Hypertension was present in 44% of CKD patients, diabetes in 38%, and cardiovascular disease in 38%. Total 53% of CKD patients were classified as stage 4 on the Kidney Disease: Improving Global Outcome (KDIGO) CKD staging. Vitamin D deficiency was observed in 26% of patients, while 39% had insufficiency. A statistically significant association was found between the severity of CKD staging and mean vitamin D levels, with lower mean levels observed in stages 4 and 5. Conclusion: Vitamin D deficiency was present in one-fourth of the CKD patients, and it was more pronounced in advanced stages of CKD.