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Abstract: PO0558

The Dietary Supplement Chitosan Lowers Serum Phosphorus in a Hemodialysis Patient Not Tolerating Prescription Binders

Session Information

Category: Bone and Mineral Metabolism

  • 402 Bone and Mineral Metabolism: Clinical


  • Sedlacek, Martin, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, United States

Group or Team Name

  • Multidisciplinary patient care team, FMC Lebanon dialysis unit, Lebanon, NH

Chitosan is a chitin derived, non-toxic, biodegradable biopolymer that binds negatively charged molecules. It's numerous industrial applications include phosphorus binding in agricultural wastewater. In humans it is used as a dietary supplement for weight loss, purportedly binding negatively charged lipids and bile acids and preventing their absorption. Here we report the case of a dialysis patient who did not tolerate prescription binders and who was able to control her serum phosphorus level for over a year by taking 3.5g of Chitosan with meals.

Case Description

A 66 y/o woman with no prior medical history and not taking any medications presented with emphysematous pyelonephritis with bilateral obstructing staghorn calculi requiring intensive care and hemodialysis. Her intial serum creatinine was 18 mg/dl. She recovered from sepsis but continued to require dialysis after discharge. Her residual creatinine clearance was 7.9ml/min six months after hospital discharge and 5.6ml/min two years later. The patient tried several prescription phosphorus binders but eventually decided to stop all prescription medications because of gastrointestinal side effects. Since over a year ago, at the recommendation of her dietitician, she purchased 500mg Chitosan tablets from the internet and used them like a phosphorus binder with meals, at a dose of 3.5 g per day. Her serum phosphorus levels have been stable and in a controlled range since (Figure 1). A quantitative analysis using urea kinetics to estimate phosphorus intake and removal reveals that Chitosan bind around 40 mg of phosphorus per gram, comparable to prescription binders.


Chitosan acts as an over-the-counter non-calcium containing phosphorus binder that may provide an alternative option for patients who do not tolerate prescription phosphorus binders. Importantly, it may be psychologically more attractive for patients to take a dietary supplement for weight loss with their meals than a prescription medication.

Figure 1: Effect of Chitosan on serum phosphorus levels