25-Hydroxyvitamin-D deficiency in chronic kidney disease stages III, IV, and V in South Asian population: a retrospective cohort

OBJECTIVE: Vitamin D deficiency in Chronic Kidney Disease is a known fact, but the data regarding the prevalence and extent of vitamin D deficiency in different stages of Chronic Kidney Disease is scarce. This leads to a delay in addressing this issue. We conducted this study to assess vitamin-D deficiency in different stages of Chronic Kidney Disease to improve the evidence available to Physicians and Nephrologists which can help them better address this common finding in Chronic Kidney Disease. METHODS: This retrospective study from a tertiary care hospital in Karachi, Pakistan, included adult Chronic Kidney Disease patients who had their serum 25 Hydroxy vitamin D levels done. The patients were classified according to stages of Chronic Kidney Disease using Estimated Glomerular Filtration Rate values. Appropriate statistical tests were performed to find a correlation between the severity of vitamin D deficiency in different stages of Chronic Kidney Disease with a statistically significant p value of <0.05 and a 95% confidence interval. RESULTS: In total, 148 patients were included in the study. All patients had serum 25 Hydroxy vitamin D levels less than 30 ng/ml. The severity of vitamin D deficiency was observed to increase progressively from stage 3A Chronic Kidney Disease through stage 5. Vitamin D levels in Chronic Kidney Disease stage 3 were significantly greater than in Chronic Kidney Disease stages 4 and 5 (p value < 0.001), and stage 5 patients had the lowest vitamin D levels in our study. Similar, statistically significant findings were observed for serum phosphate levels, too, with stage 5 Chronic Kidney Disease patients having a greater serum phosphate concentration than stages 3A and 3B (p value = 0.002, 0.006). CONCLUSION: All Chronic Kidney Disease patients in our study either had vitamin D insufficiency or deficiency. In addition, we observed a significant decrease in vitamin D levels from Chronic Kidney Disease stage 3 to stage 5. Greater serum phosphate levels were detected in stage 5 compared to stages 3A and 3B.