Alfacon nutritional supplement contains amino acids, partly in form of there corresponding ketoanalogues, essential for patients with chronic kidney disease. It follows same catabolic pathways as amino acids and works by improving the metabolism of protein in the body, thereby improving the renal function. Alfacon allows the intake of essential amino acids while minimizing the amino-nitrogen intake. The keto- and hydroxy-analogues are transaminated to the corresponding essential amino acids by taking nitrogen from non-essential amino acids, thereby decreasing the formation of urea by re-using the amino group, and causes absorption to occur.