Background: Investigate whether changes in vitamin D levels affected erythropoiesis stimulating agent (ESA) requirements in chronic kidney disease (CKD) patients with anemia.
Methods: A retrospective cohort study of nondialysis-dependent patients with CKD of all stages. Patients were anemic and on ESA with at least 2 documented 25-hydroxylated vitamin D (D25) levels drawn 4 months apart. Patients were grouped based on the change in their D25 levels. The primary end point evaluated was absolute change in the ESA doses needed to maintain target hemoglobin levels between 11 and 12 g/dl.
Results: A total of 153 patients met the inclusion criteria for analysis. With the exception of the normal-to-low D25 group, patients showed a trend toward lower ESA doses with time. The low-to-normal vitamin D group showed a significant reduction in dose of 24% (1,415 units, p = 0.025). The normal-to-low group, however, showed a 22% increase in dose of 1,270 units (NS). Levels of Ca, PTH, and iron indexes were similar across all groups.
Conclusion: Our retrospective cohort study demonstrates an ESA sparing effect in patients with vitamin D deficiency after repletion to normal levels. Conversely, there was a trend toward increased ESA requirements in patients who became vitamin D deficient from a previously normal state.