From the Guidelines
Limiting dietary phosphate intake is suggested in the treatment of hyperphosphatemia alone or in combination with other treatments, especially in patients with chronic kidney disease (CKD) G3a to G5D 1. When considering a high phosphorus diet, it's essential to understand that phosphorus is crucial for bone health, energy production, and cell function. Good sources of phosphorus include dairy products, protein-rich foods, nuts, seeds, whole grains, and legumes. However, processed foods with phosphate additives should be consumed in moderation due to their highly absorbable phosphorus content. Key points to consider:
- Phosphorus intake should be limited in patients with hyperphosphatemia, especially those with CKD 1.
- The source of phosphate (e.g., animal, vegetable, additives) should be considered when making dietary recommendations 1.
- Excess exposure to calcium may be harmful across all GFR categories of CKD, and phosphate-lowering treatment decisions should be individualized 1.
- Patients with CKD should focus on natural food sources rather than supplements unless medically advised, and always consult a healthcare provider before significantly changing their diet, especially if they have existing health conditions or take medications that might affect phosphorus levels 1.
From the FDA Drug Label
High intake of calcium and phosphate concomitant with calcitriol may lead to similar abnormalities. The serum calcium times phosphate (Ca x P) product should not be allowed to exceed 70 mg2/dL2. Treatment of Hyperphosphatemia in Predialysis Patients If serum phosphorus levels exceed 5.0 mg/dL to 5.5 mg/dL, a calcium-containing phosphate-binding agent (i.e., calcium carbonate or calcium acetate) should be taken with meals.
A high phosphorus diet may lead to hyperphosphatemia when taken concomitantly with calcitriol. To manage hyperphosphatemia, a calcium-containing phosphate-binding agent should be taken with meals if serum phosphorus levels exceed 5.0 mg/dL to 5.5 mg/dL. The serum calcium times phosphate (Ca x P) product should not exceed 70 mg2/dL2 2.
From the Research
High Phosphorus Diet and Its Implications
- A high phosphorus diet can lead to hyperphosphatemia, which is an independent risk factor for mortality in patients on maintenance dialysis 3.
- Phosphate overload is a dramatic consequence in end-stage renal disease (ESRD) patients, and elevated serum phosphate and calcium-phosphate product levels play an important role in the pathogenesis of secondary hyperparathyroidism and extra-skeletal calcification in dialysis patients 4.
Management of Hyperphosphatemia
- Dietary phosphorus restriction is essential for attenuating increased serum levels, but it is relatively underutilized due to logistical complexity and fear of worsening protein-energy wasting 3.
- Phosphate binders are used widely to prevent absorption of dietary phosphorus, and new calcium- and aluminum-free phosphate binders, such as lanthanum carbonate, can be used to treat hyperphosphatemia and secondary hyperparathyroidism in ESRD patients 4.
- A systematic review of recent data on phosphate binders in chronic kidney disease (CKD) summarizes the latest information on non-pharmacological measures, effects of phosphate binders on morbidity and mortality, and new information on specific aspects of various phosphate binders 5.
Current Perspectives on Phosphate Binder Use
- The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) suggests lowering elevated phosphate levels towards the normal range with possible strategies including dietary phosphate restriction or use of binders 6.
- Many different classes of phosphate binders are now available, but clinical trials have not definitively demonstrated the superiority of any class of phosphate binders over another with regard to clinical outcomes 6.
- The choice of phosphate binder depends on various factors, including the patient's individual needs, side effects, and cost 6, 7.