Understanding phosphorus: Diet and medication management

Hyperphosphatemia, an increase in phosphorus levels, is commonly seen with the progression of chronic kidney disease (CKD). As organ function is lost, the kidneys are unable to excrete excess phosphorus. This results in an accumulation in the body and elevated blood levels. While the negative impact on mineral and bone health is well known, hyperphosphatemia also increases the risk for cardiovascular disease (CVD) and vascular calcification.  

Treatments recognized for this condition include diet modifications, phosphorus binder medications, and dialysis. As part of an interdisciplinary team approach with patients, the registered dietitian nutritionist (RDN) can highlight the importance of diet and the role of nutrition in disease management. 

What do the nutrition guidelines say? 

Updated in 2020, the National Kidney Foundation’s (NKF) Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Nutrition in CKD provides a reference for RDNs in terms of phosphorus goals. According to the guideline, a phosphorus blood value between 2.5 and 4.5 mg/dL is recommended.  

To reach this measure, previous standards targeted a specific daily amount of dietary phosphorus. Now, experts suggest a more individualized approach by adjusting intake to maintain labs within the normal range. Taking a closer look at food sources and phosphate bioavailability can help reach this goal.  

What are the differences in phosphorus bioavailability in food? 

24-hour food recalls, 3-day food records, or food frequency questionnaires can be utilized in evaluating a patient’s type and amount of phosphorus intake. Depending on the food, the phosphate type will impact nutrient bioavailability. Organic phosphorus is found in plant or animal-based sources such as legumes, nuts, seeds, whole-grains, meat, poultry, seafood, and dairy products.  

Of these selections, an average of 40 to 60% of the phosphorus consumed is absorbed. More specifically, plant-based foods have lower overall absorption (closer to 40%) because they contain phytic acid, a storage form of phosphorus. Humans lack the phytase enzyme needed to break down phytic acid as it passes through the gastrointestinal (GI) tract, limiting absorption.  

As part of a healthy diet, choices with organic phosphorus should be encouraged. Foods containing inorganic phosphorus are more of a concern due to the risk associated with chronic disease. This type of phosphate is readily absorbed at 90 to 100% of the amount consumed. Examples of choices with inorganic phosphorus, in the form of phosphorus additives, include processed foods, enhanced meats, certain bottled beverages, and fast food.  

The importance of label reading 

Since phosphorus is not required as part of the Nutrition Facts Label, finding sources requires a scan of the ingredient list.  Phosphorus additives can be identified as they contain the phrase “phos” as part of their name.  

Common phosphate additives found in food items are: 

• Phosphoric acid 
• Monosodium phosphate  
• Dicalcium phosphate 
• Disodium phosphate 
• Trisodium phosphate 

Patient avoidance of foods with hidden phosphate additives is necessary as part of a low-phosphorus diet. Nutrition education should focus on the importance of reading labels to identify these additives in food ingredients better. 

What is a phosphorus binder? 

Phosphate binders are prescribed with meals or snacks for the individual with CKD or on dialysis to help maintain normal phosphorus blood values. Acting in the GI tract, these medications bind with phosphorus from foods to create an insoluble complex that is excreted with stool. Binders are unable to negate all dietary phosphorus and, on average, absorb 300 mg or less per day. 

Depending on the type, binder medications can be prescription or over-the-counter options. The type recommended is individualized based on the patient and laboratory values. 

Calcium-based phosphorus binders:  

• Examples: TUMS® (calcium carbonate), PhosLo® (calcium acetate) 
• Monitor: Lab values of calcium, phosphorus, and parathyroid hormone (PTH) 
• Contraindications: Individuals with hypercalcemia or low PTH 

Non-calcium-based phosphorus binders:  

• Examples: Renvela® (sevelamer carbonate), Renagel® (sevelamer hydrochloride), Fosrenol® (lanthanum carbonate) 
• Monitor: Lab values of calcium, phosphorus, and PTH 
• Contraindications: History of bowel obstruction 

Iron-based phosphorus binders: 

• Examples: Auryxia® (ferric citrate) and Velphoro® (sucroferric oxyhydroxide) 
• Monitor: Lab values of iron, transferrin saturation, ferritin, hemoglobin, calcium, phosphorus, and PTH 
• Contraindications: Iron overload syndrome, hypersensitivity to iron supplementation, history of bowel obstruction 

Aluminum-based phosphorus binders:  

• Examples: Amphojel® (aluminum hydroxide), AlternaGEL® (aluminum hydroxide) 
• Monitor: Aluminum levels and serum phosphorus 
• Contraindications: Not routinely recommended for patients due to the risk for aluminum toxicity 

Magnesium-based phosphorus binders:  

• Example: MagneBind® (magnesium carbonate with additional calcium carbonate and folic acid) 
• Monitor: Lab values of calcium, phosphorus, PTH, and magnesium 
• Contraindications: Individuals with hypermagnesemia (risk for toxicity) or not requiring dialysis   

Nutrition barriers for the patient 

With CKD, treatment with medications, diet, and dialysis can contribute to a perceived decrease in quality of life. Phosphorus management adds to this concern with diet restrictions and pill burden. The need to take phosphate binders with meals and snacks as part of a daily routine can be a struggle. Pills can be large and difficult to swallow.  

On average, phosphorus binders account for approximately half of the total pills for the CKD patient. Experts emphasize the need for individualized care and the use of patient-centered, achievable diet goals to help improve quality of life. Additionally, research remains ongoing for alternative phosphate binder options to lessen the pill quantity needed by patients with CKD.  

A dietitian’s role 

Patient understanding of phosphorus and the impact of this nutrient on their health can be complicated. Not only does hyperphosphatemia negatively impact mineral and bone disease, but it can also result in CVD and vascular complications when left uncontrolled. The dietitian plays an important role in patient care by providing detailed nutrition education, helping suggest healthy diet modifications, and encouraging phosphorus binder adherence.    

Dietitians On Demand is a nationwide staffing and recruiting company for registered dietitians, specializing in short-term, temporary, and permanent-hire positions in acute care, long-term care, and food service. We’re dedicated to dietitians and helping them enhance their practice and excel in the workplace. Check out our job openings, request your coverage, or visit our store today!

References

Biruete A, Gallant K, Lloyd L, et al. “Phos”tering a clear message: The evolution of dietary phosphorus management in chronic kidney disease. J Ren Nutr. 2023;33(6S):S13-S20. doi: 10.1053/j/jrn.2023.05.004. 

Forfang D, Edwards D, Kalantar-Zadeh K. The impact of phosphorus management today on quality of life: Patient perspectives. Kidney Med. 2022;4(4):100437. doi: 10.1016/j.xkme.2022.100437.   

Ikizler TA, Burrowes JD, Byham-Gray LD, et al; KDOQI Nutrition in CKD Guideline Work Group. KDOQI clinical practice guideline for nutrition in CKD: 2020 update. Am J Kidney Dis. 2020;76(3)(suppl 1):S1-S107. doi: 10.1053/j.ajkd.2020.05.006. 

National Kidney Foundation. Phosphorus and Your Diet.  https://www.kidney.org/kidney-topics/phosphorus-and-your-diet. Accessed June 9, 2025. 

Gonyea J, Phillips S, eds. A Clinical Guide to Nutrition Care in Kidney Disease. 3rd edition. Academy of Nutrition and Dietetics;2023. 

McCann L, ed. CKD Mineral and Bone Disorder (CKD-MBD). In: Pocket Guide to Nutrition Assessment of the Patient with Kidney Disease. 6th edition. National Kidney Foundation;2021, pp. 8.14-8.16.