Combination vitamin D therapy in stage 5 chronic kidney disease

To review the data supporting combination therapy with vitamin D and vitamin D receptor activators (VDRAs) in patients with stage 5 chronic kidney disease (CKD).

Literature was searched using PubMed and EMBASE using the terms kidney disease, kidney failure-chronic, and vitamin D. Limits applied included humans, adults (19 years or older), and clinical trials (and related), with publication dates between January 1, 1980, and May 16, 2011.

All English-language publications were analyzed for relevance. Studies appropriate to the objective were evaluated, including 3 prospective observational studies, 1 prospective cohort study, and 1 retrospective study.

To our knowledge, there have been no randomized controlled trials evaluating the safety and efficacy of vitamin D supplementation in combination with VDRA therapy in patients with stage 5 CKD. Relatively small observational studies have demonstrated improvements in 25-hydroxyvitamin D (25-OHD) concentrations and markers of mineral and bone metabolism as well as reduced VDRA use in patients with stage 5 CKD. Not all patients in these studies were receiving VDRA therapy. Therapy was safe, with no patients exceeding the recommended upper limit for 25-OHD concentrations and only a small percentage experiencing transient/correctable hypercalcemia.

Vitamin D supplementation to maintain 25-OHD concentrations at 20-30 ng/mL or higher with or without VDRA therapy is inexpensive, appears safe, and may have additional health benefits in patients with stage 5 CKD. Well-designed, randomized controlled trials are needed to determine the efficacy and safety of combination vitamin D therapy in patients with stage 5 CKD.