Vitamin D Compounds Have Uncertain Benefit in Kidney Disease

Results of a meta-analysis indicate that efficacy is unproven.

Patients with chronic kidney disease often have elevated parathyroid hormone (PTH) levels and related effects on calcium metabolism and bone. Active vitamin D compounds (e.g., 1--hydroxyvitamin D₃, calcitriol) are routinely prescribed to counter secondary hyperparathyroidism. To examine the effects of vitamin D compounds on biochemical and clinical outcomes, researchers conducted a meta-analysis of data from 76 randomized trials (involving 3667 patients) of active vitamin D compounds (including newer analogues) in patients with chronic kidney disease.

Older vitamin D compounds did not consistently lower PTH levels, although most studies suggested some reduction. Furthermore, older compounds increased risk for hypercalcemia and hyperphosphatemia. Newer vitamin D analogues lowered PTH levels but also increased risk for hypercalcemia. Vitamin D compounds did not affect bone pain, fracture risk, need for parathyroidectomy, requirement for renal replacement, creatinine clearance, or mortality.

Comment: It’s unsettling when careful analysis suggests that a routine, established practice with a solid pathophysiologic rationale is not beneficial. In this case, the dearth of studies with important clinical outcomes could explain some of the lack of evidence for benefit. An editorialist concludes that using vitamin D compounds in patients with chronic renal disease is costly, provides no proven benefit, and has the potential to be harmful. He suggests that practice change to reflect the evidence; however, his suggestion likely will meet resistance from those who advocate routine use of vitamin D compounds and from drug companies that manufacture them.

— Richard Saitz, MD, MPH, FACP, FASAM

Published in Journal Watch General Medicine January 17, 2008

Citation(s):

Palmer SC et al. Meta-analysis: Vitamin D compounds in chronic kidney disease. Ann Intern Med 2007 Dec 18; 147:840.