Dosing Supplements for Dialysis Patients

April 28, 2015
Jeannette Y. Wick, RPh, MBA, FASCP

Traditionally, dialysis patients receive a supplemental renal vitamin containing a mixture of B and C vitamins, but recent research has suggested a potential role for other vitamins and minerals, as well.

Nearly 1 million adults in the United States experience end-stage renal disease (ESRD), and about half receive some type of dialysis. The United States spent $40 billion treating ESRD patients in 2009 alone, so researchers remain dedicated to improving existing dialysis treatment and patient outcomes.

Traditionally, dialysis patients receive a supplemental renal vitamin containing a mixture of B and C vitamins, but recent research has suggested a potential role for other vitamins and minerals, as well.

For instance, a recent study published in BMC Nephrology evaluated the effectiveness of daily zinc and selenium supplementation in improving serum levels of each mineral in hemodialysis patients at 90 and 180 days. The researchers compared 2 therapeutic regimens to the standard renal vitamin: the addition of vitamin E and low- or high-dose zinc and selenium (250 IU, 25 mg, 50 mcg versus 250 IU, 50mg, and 75 mcg).

The primary outcome was the percentage of participants in the treatment groups with low serum zinc levels at 90 days compared with the control subjects. Secondary outcomes included zinc levels at 180 days, selenium levels at 90 and 180 days, salt sensitivity, weight gain between dialysis sessions that generally reflects fluid retention, and adverse events.

This randomized, double-blinded clinical trial study was limited to only 150 participants. The doses chosen were conservative compared with recent trials, and vitamin E’s effects were not included as an outcome.

Nevertheless, the data was analyzed both before and after, correcting for the number of participants with deficient levels prior to treatment, defined as <815 mcg/L for zinc and <121mcg/L for selenium.

Although the researchers noted a significant increase in serum zinc and selenium at 90 days for the high-dose intervention group compared with control subjects, they concluded zinc and selenium supplementation at the studied doses do not correct for insufficiency overall. Further research is needed to evaluate higher dosages, parenteral supplementation, and the role zinc and selenium levels play in dialysis patient outcomes.