FRIDAY, May 16 (HealthDay News) -- Taking activated vitamin D may cut the risk of death for people with moderate to severe chronic kidney disease by about one quarter, a new study suggests.

During a two-year study of more than 1,400 patients, those being treated with calcitriol, an oral form of activated vitamin D, had their overall risk of death lowered by 26 percent when compared with those not on the drug. Those taking calcitriol were also less likely to develop end-stage renal disease, which requires dialysis to replace lost kidney function.

Patients with advanced chronic kidney disease (CKD) often take calcitriol to treat elevated levels of parathyroid hormone (hyperparathyroidism), a condition that can weaken the bones.

"Although activated vitamin D is known to influence many biological processes, previous clinical knowledge is limited to its effect on parathyroid hormone levels," study co-author Dr. Bryan Kestenbaum, of the University of Washington in Seattle, said in a prepared statement.

Overall, calcitriol use was linked to a 20 percent reduction in the likelihood of either dying or needing dialysis. The reduction in mortality with calcitriol appeared to be unrelated to its effect on parathyroid hormone levels.

The study is published in the August issue of the Journal of the American Society of Nephrology.

The lack of data on other factors that may have improved survival rates in patients taking calcitriol does limit the study's conclusions, as does the narrow range of demographics among its subjects, the study added. Those studied were primarily older, white men, so the results are not guaranteed to repeat when treatment is given to a younger, more ethnically diverse population with chronic kidney disease (CKD).

"Randomized clinical trials are needed to test the hypothesis that vitamin D therapy can improve cardiovascular health and survival in CKD," Kestenbaum said. "Future studies should also examine the role of non-activated vitamin D, which is less expensive and less toxic."

More information

The U.S. National Library of Medicine has more about the causes and treatment of kidney failure.

-- Kevin McKeever

SOURCE: American Society of Nephrology, news release, May 2008

Copyright © 2008 ScoutNews, LLC. All rights reserved.