Which of the following is recommended to control serum phosphate in CKD patients?

• A. Calcium carbonate and calcium gluconate
• B. Vitamin D therapy
• C. Sevelamer
• D. Erythropoietin

Answer: (C)

Phosphate control in CKD is achieved by preventing intestinal absorption of phosphate with a binder. Sevelamer is a non-calcium, non-metal phosphate binder that binds phosphate in the gut and lowers its absorption, reducing serum phosphate without adding calcium. This is advantageous because calcium-based binders can raise calcium levels and the calcium-phosphate product, promoting vascular calcification in CKD. Vitamin D therapy helps with secondary hyperparathyroidism but does not directly reduce phosphate—and it can increase phosphate absorption in some cases. Erythropoietin treats anemia, not phosphate handling. So sevelamer best achieves phosphate control while avoiding extra calcium load and related complications.