Evaluation of Effect of Vitamin D Deficiency on Anemia and Erythropoietin Hyporesponsiveness in Patients of Chronic Kidney Disease.

BACKGROUND: The role of vitamin D deficiency and inflammation levels in renal anemia has been documented. However, no study is available in India where the role of vitamin D supplementation in patients with hyporesponsiveness to increased doses of erythropoietin is available. Hence this study.

MATERIAL AND METHODS: This study was conducted on 50 adult patients of CKD, on regular, twice weekly hemodialysis. It included 38 cases in group A with deficient serum vitamin D levels (<30 ng/ml) and 12 cases in group B with sufficient vitamin D levels (>30 ng/ml). Both groups of cases were receiving erythropoietin in a dose of 4000 I.U. subcutaneously twice weekly following dialysis and had failed to show rise in hemoglobin (Hb) >1gm/dl after one month, hence erythropoietin was increased to 6000 I.U. Group A was given additional vitamin D in a dose of 60000 I.U. orally, once a week for next three months along with erythropoietin 6000 I.U. where as Group B served as control. Hematological and renal parameters, ESR, high sensitivity C reactive protein (HsCRP) and serum ferritin were estimated at baseline and then at one monthly intervals for next four months. Parathyroid hormone (iPTH), serum B12, folic acid and vitamin D (25OHD3) were measured at the start and end of the study only. Erythropoietin resistance index (ERI) was calculated to evaluate dose response.

RESULTS: Basal ERI, HsCRP and ESR and serum ferritin were raised in both the groups. At the end of four months, there was a significant increase in the Hb and hematocrit (Hct) (p<.001) and a significant fall in ERI, ESR, HsCRP, serum ferritin and iPTH (p<.001) in group A. Group B, also had a significant increase in the hemoglobin and hematocrit (p<.001) and decrease in ERI, ESR, HsCRP, serum ferritin and iPTH which was not significant. Basal vitamin D and ERI had a positive and insignificant correlation (r=0.05; p=0.756) in group A where as a negative and insignificant correlation was observed between them at the end of four months (r= -0.195; p >0.05).

CONCLUSIONS: vitamin D play an important role in reducing inflammation and thereby in the cure of anemia in EPO hyporesponsive CKD patients and needs to be supplemented, if deficiency is found.