Vitamin D3 repletion in chronic kidney disease stage 3: effects on blood endotoxin activity, inflammatory cytokines, and intestinal permeability.

BACKGROUND: Vitamin D deficiency is common in the general population and even more prevalent in patients with chronic kidney disease (CKD). Low 25-hydroxyvitamin D [25(OH)D] levels have been associated with cardiovascular disease, though a definitive mechanistic link has not been established. Further, it is unclear if repleting vitamin D mitigates the excess risk observed in epidemiologic studies. Because vitamin D may regulate innate immunity and gut epithelial differentiation, we hypothesized that oral cholecalciferol (D3) would result in decreased blood endotoxin activity, a potential risk factor for cardiovascular disease. STUDY DESIGN, SETTING & PARTICIPANTS, INTERVENTION: We studied 12 stable outpatients with CKD stage 3 and 25(OH)D deficiency, who received D3 30,000 units weekly for 8 weeks. The primary endpoint was the change in blood endotoxin activity.

RESULTS: Baseline endotoxin activity correlated with 25(OH)D levels (r = -0.60, p = 0.04). Endotoxin activity decreased by 25% from baseline (p = 0.03). Despite the decrease in endotoxin activity, there was no change in intestinal permeability.

CONCLUSION: The results of this study suggest that vitamin D repletion therapy may have an effect on endotoxin activity in early CKD. Further intervention studies using vitamin D in the CKD population are required.