Does vitamin D therapy improve survival in patients with CKD?

For patients with chronic kidney disease (CKD), vitamin D therapy does little to reduce the risk of all-cause death, according to a study.

Researchers conducted a systematic review and meta-analysis. Multiple online data bases were searched for relevant randomized controlled trials (RCTs) with ≥3 months follow-up in which the effects of a vitamin D compound were evaluated in adults with stage 3, 4, or 5 CKD, including kidney failure treated with dialysis. Recipients of a kidney transplant were excluded.

Random effects meta-analysis was used to summarize treatment estimates, with primary endpoints being all-cause death, cardiovascular death, and fracture. Secondary endpoints included major adverse cardiovascular events, hospitalization, bone mineral density, parathyroidectomy, progression to kidney failure, proteinuria, estimated glomerular filtration rate, hypercalcemia, hyperphosphatemia, biochemical markers of CKD-mineral and bone disorder (CKD-MBD), and various intermediate outcome measures of cardiovascular disease. Risk of bias and evidence certainty were also assessed.

The meta-analysis included 128 studies involving 11,270 participants. Pooled data showed that compared with placebo, vitamin D therapy had no effect on all-cause death (relative risk [RR], 1.04, 95 percent confidence interval [CI], 0.84–1.24) and had uncertain effects on fracture (RR, 0.68, 95 percent CI, 0.37–1.23) and cardiovascular death (RR, 0.73, 95 percent CI, 0.31–1.71).

Meanwhile, vitamin D therapy led to a decrease in serum parathyroid hormone and alkaline phosphatase but an increase in serum calcium when compared with placebo.

This meta-analysis was limited by inclusion of trials with short-term follow-up, small sample size, and the suboptimal quality.