Vitamin D for Kidney Disease Unproven
Review of 76 Studies Shows Value of Vitamin D Treatment for Chronic Kidney Disease 'Uncertain'
The Analysis: Vitamin D for Kidney Disease
Palmer, Strippoli and their colleagues searched medical databases from
January 1966 through July 2007 to find published studies of vitamin D compounds
for chronic kidney disease. They selected 76 that met their criteria for
inclusion. In all, 3,667 participants were in these 76 studies.
When they pooled the results and analyzed them, the researchers found that
the vitamin D compounds did not consistently reduce the parathyroid hormone
levels or reduce the risk of death, bone pain, blood vessel calcification, or other problems.
When they compared the established vitamin D sterols with placebo, the
vitamin D treatments were associated with a 2.3 times higher risk of high
calcium levels and a nearly two times higher risk of high phosphate in the
blood. And the treatment didn't consistently reduce the parathyroid hormone
Newer types of vitamin D treatment did not perform better.
The analysis is published in the Annals of Internal Medicine.
In an editorial accompanying the analysis, Marcello Tonelli, MD, associate
professor of medicine at the University of Alberta in Edmonton, Canada, writes:
"Palmer and colleagues' findings should serve as yet another warning to the
nephrology community that we do not have good evidence to defend many of our
"We need to do more research," Tonelli tells WebMD. "To figure
out the best role for these medicines, a large trial or trials are needed,
probably funded by a U.S. government agency such as the National Institutes of
He reports as a potential conflict of interest that he receives funding from
the Centre for D-Receptor Activation Research to examine vitamin D status in
remote-dwelling patients on dialysis.
Message for Kidney Disease Patients
Strippoli and Palmer, too, call for more research in the area to prove the
Meanwhile, those with chronic kidney disease should follow their doctors'
advice, Strippoli says. Until more is known, patients should closely follow, in
particular, advice about preventive measures suggested by their doctors,
including dietary advice and recommendations to undergo longer dialysis