Vitamin D Plus a Phosphorus Binder Improves Survival
SAN DIEGO—A study of Japanese dialysis patients demonstrated that a combination of oral vitamin D and a phosphorus binder is associated with lower mortality.
The study, by Tsuneo Konta, MD, PhD, Associate Professor of Nephrology at Yamagata University School of Medicine in Yamagata, Japan, included 466 patients at 17 hospitals who were on maintenance dialysis at the end of 2003.
Investigators divided patients into one of four groups. One group received both oral vitamin D and a phosphorus binder (reference group); another group received neither medication; a third group received oral vitamin D but not a phosphorus binder; and the fourth group received a phosphorus binder but not vitamin D. Investigators followed patients for up to five years.
Compared with the reference group, the patients who did not take either drug had a significant 3.5 times increased risk of death, after adjusting for age, gender, duration of dialysis, and numerous other variables. Patients who took a phosphorus binder but not vitamin D had a significant twofold increased mortality risk. Subjects who took vitamin D but not a phosphate binder had a nonsignificant 38% increased mortality risk.
The findings indicate “that the concomitant use of vitamin D and phosphorus binder was an independent predictor of survival in dialysis patients,” the authors noted in a poster presented here at the American Society of Nephrology's Renal Week conference.
Dr. Konta told Renal & Urology News, “This study suggests that to optimize the dialysis patients' prognosis, the concomitant use of vitamin D and phosphorus binder under tight control of serum calcium and phosphate levels is recommended.”
The researchers did not observe a significant association between the dual treatment and improved survival in patients with high serum calcium levels (above 10 mg/dL) or phosphate levels (above 6 mg/dL).