Phosphorus Knowledge and Dietary Intake of Phosphorus of US Adults Undergoing Dialysis

Abnormal serum phosphorus is a concern for adults undergoing dialysis due to the risk for mortality and morbidity. General recommendations for maintaining serum phosphorus within normal limits is monitoring dietary intake of phosphorus and taking phosphate binders, as prescribed. However, limited research is available about adults' phosphorus knowledge and dietary intake of phosphorus. The purpose of this cross-sectional study was to determine the association between phosphorus knowledge and dietary intake of phosphorus of adults on dialysis. An online Qualtrics survey was conducted during February-September 2023. Participants (n = 107) responded to the 74-item questionnaire (30-day food frequency questionnaire, phosphorus knowledge questionnaire, and demographic questions). Analysis included frequencies, descriptive statistics, t-tests, and Spearman correlations. JMP SAS v16 was used with a statistical significance of p < 0.05. Of the participants, 57.0% (n = 61) were on peritoneal dialysis and 43.0% (n = 46) were on hemodialysis. Average phosphorus knowledge score was 10.6 ± 3.0 out of 19 or 55.8%, with those on peritoneal dialysis having lower scores (54.7%) compared to participants on hemodialysis (58.1%) (p < 0.05). The daily average dietary phosphorus intake was 605 ± 297 mg. Participants on peritoneal dialysis consumed more phosphorus (625 mg) compared to participants on hemodialysis (576 mg) (p < 0.05). There was no association with phosphorus knowledge scores and dietary intake of phosphorus. There were positive correlations between discussing about phosphorus, knowing serum phosphorus concentration, and phosphorus knowledge scores. These results can aid practitioners in providing tailored nutrition education among adults on dialysis.