Dialysis Patients: Longer Lives With Vitamin D?
Better Survival for Patients Taking Injected Vitamin D, Study Shows
March 1, 2005 -- Vitamin D injections may help kidney dialysis patients live longer.
A new study indicates that vitamin D injections, given to patients with kidney failure, results in a significantly reduced risk of death compared to those who do not receive the treatment.
Dialysis does the work of healthy kidneys. Short of getting a kidney transplant, dialysis is the only way for patients with severe kidney failure to stay alive. It helps clear toxins from the body.
However the kidney has another main function. It produces several important hormones including vitamin D. Because dialysis patients commonly have vitamin D deficiency they usually get vitamin D shots.
Vitamin D has been associated with improved survival in different settings, including improved cancer survival and infection survival rates, write the authors. Yet according to the authors, no large studies have looked at the potential survival benefit of injectable vitamin D in people with kidney failure.
"This finding was a surprise and should force us to think more broadly about who should be treated," says researcher Ravi Thadhani, MD, MPH, in a news release. "We at least need to be more aggressive in treating people who meet the current criteria." Thadhani works at Massachusetts General Hospital in Boston.
Vitamin D and Dialysis
Vitamin D deficiencies aren't unusual, especially among dialysis patients, says the study. The consequences of a vitamin D shortfall extend throughout the body.
But is it a matter of life and death for dialysis patients? That's a key question. More than 67,000 people per year in America die as a result of kidney failure, and there are more than 275,000 dialysis patients in the U.S., says the National Kidney Foundation.
About half of U.S. dialysis patients currently get vitamin D shots, says the Massachusetts General Hospital news release.
Vitamin D: How Great Is the Survival Advantage?
The study included more than 51,000 dialysis patients. All had been on dialysis for at least 90 days. Vitamin D shots were given to more than 37,000 participants. The other participants had not received the shots.
The researchers tracked the patients' survival for two years. At the study's end, 76% of the vitamin D group was still living, compared with 59% of those who didn't get vitamin D shots.
Those who received vitamin D shots during the two-year study had a 20% reduced risk of death compared with those who did not receive the vitamin shots.
They also had lower rates of deaths from heart problems and infections.
Age, gender, race, diabetes status, weight, and other considerations didn't change the results much. "The group that received injectable vitamin D had a significant survival advantage over patients who did not," write the researchers.
The advantage was seen with any form of injected vitamin D. Previously, the researchers had found that a type of injectable vitamin D called paracalcitol provided a survival advantage over calcitriol, the standard form of injectable vitamin D.
The new study didn't delve into the details about which type of vitamin D is best. Instead, it indicates that vitamin D -- in any form -- may help dialysis patients live longer. Until that's verified, treatment recommendations may not change.
The study appears in the express online edition of the Journal of the American Society of Nephrology.