Translation of Nutrient Level Recommendations to Control Serum Phosphate Into Food-Based Advice.

The control of hyperphosphatemia is key to the management of chronic kidney disease mineral and bone disorder. Dietary restriction of phosphorus is essential to control hyperphosphatemia. Guidelines for chronic kidney disease and end-stage kidney disease generally provide high-level guidance on whether a nutrient should be restricted e.g, restrict dietary phosphorus. Dietitians translate such guidance into nutrient-based strategies and finally into food-based practical dietary advice for patients to follow. The practical aspects of dietary advice are not well described in the literature, neither are the challenges of concurrently altering 1 nutrient e.g., phosphorus while continuing to restrict others e.g., potassium, while maintaining overall nutritional adequacy and quality of life. In this article, we describe how we translated updated nutrient level recommendations into practical dietary advice to be delivered at the bedside.

Revising Dietary Phosphorus Advice in Chronic Kidney Disease G3-5D.

We summarize how practicing dietitians combined available evidence with clinical experience, to define revised dietary recommendations for phosphorus in chronic kidney disease G3-5D. As well as a review of the evidence base, 4 priority topics were reviewed. These were translated into 3 nutrient level recommendations: the introduction of some plant protein where phosphorus is largely bound by phytate; consideration of protein intake in terms of phosphorus load and the phosphorus to protein ratio; and an increased focus on avoiding phosphate additives. This review summarizes and interprets the available evidence in order to support the development of practical food-based advice for patients with chronic kidney disease.

Pilot Randomized Controlled Trial of a Standard Versus a Modified Low-Phosphorus Diet in Hemodialysis Patients.

INTRODUCTION: The standard low-phosphorus diet restricts pulses, nuts, and whole grains and other high phosphorus foods to control hyperphosphatemia. We conducted a randomized controlled trial to evaluate the effectiveness, safety, and tolerability of the modified diet, which introduced some pulses and nuts, increased the use of whole grains, increased focus on the avoidance of phosphate additives, and introduced the prescription of low-biological-value protein such as bread. METHODS: We conducted a multicenter, pragmatic, parallel-arm, open-label, randomized controlled trial of modified versus standard diet in 74 adults on hemodialysis with hyperphosphatemia over 1 month. Biochemistry was assessed using monthly laboratory tests. Dietary intake was assessed using a 2-day record of weighed intake of food, and tolerability was assessed using a patient questionnaire. RESULTS: There was no significant difference in the change in serum phosphate between the standard and modified diets. Although total dietary phosphorus intake was similar, phytate-bound phosphorus, found in pulses, nuts, and whole grains, was significantly higher in the modified diet (P < 0.001). Dietary fiber intake was also significantly higher (P < 0.003), as was the percentage of patients reporting an increase in bowel movements while following the modified diet (P = 0.008). There was no significant difference in the change in serum potassium or in reported protein intake between the 2 diets. Both diets were similarly well tolerated. CONCLUSION: The modified low phosphorus diet was well tolerated and was associated with similar phosphate and potassium control but with a wider food choice and greater fiber intake than the standard diet.

Lack of correlation between calcium intake and serum calcium levels in stable haemodialysis subjects.

BACKGROUND: The relationship between calcium intake and serum calcium level in hemodialysis patients is poorly understood. METHODS: We quantify total oral calcium intake using detailed 7-day food diaries with 294 patient days of observation in 42 stable, non-diabetic hemodialysis subjects. RESULTS: Mean (SD) albumin-corrected serum calcium was 9.84 mg/dl (0.8). The albumin-corrected serum calcium was low (<8.4 mg/dl) in 2 patients, low-normal (8.4-9.49) in 9 patients, high-normal (9.5-10.2) in 18 patients and high (>10.2) in 13 patients. Mean (SD) total (diet plus binder) oral calcium intake was 1996 mg/day (1,020); 16 patients (38%) had a total calcium intake >2,000 mg/day. Calcium intake and serum calcium were poorly correlated (Spearman rank method), r = 0.14, p = 0.39. Median calcium intakes were similar in those with normal (1,990 mg/day), high-normal (1,926 mg/day) and high calcium groups (1,713 mg/day), p = 0.73 (Kruskal-Wallis), p = 0.29 (linear test for trend). Forty-one percent (11/27) of patients who had serum calcium in the normal range had a calcium intake greater than 2 g/day, while 11.5% had a calcium intake greater than 3 g/day. In subjects with a parathyroid hormone (PTH) concentration <300 pg/ml (n = 20), the correlation between calcium intake and either uncorrected serum calcium or albumin-corrected serum calcium was stronger, r = 0.45, p = 0.05 and r = 0.38, p = 0.10, respectively, though there remained wide variability in calcium intake. CONCLUSION: Serum calcium is not a reliable indicator of calcium intake, especially at PTH > or = 300 pg/ml. An excessive calcium intake may coexist with a normal serum calcium level.