Nutrition plays a critical role in managing the signs and progression of kidney problems. Iams® Veterinary Formulas Renal -Multi-Stage RenalTM/Feline nutritionally manage progression with:patented Nitrogen Trap Fiber System, which diverts the waste products of protein metabolism from the bloodstream into the colon, thereby reducing the workload on the failing kidneys. This allows for optimal protein intake to maintain muscle mass, immune system and glomerular filtration (filtering of fluids through the kidneys).omega-6:omega-3 fatty acid ratio targeting 5:1, which helps reduce intrarenal blood pressure, helps minimize inflammation and helps slow progression. Potassium citrate is added to counter the effects of metabolic acidosis (a condition in which the pH of the blood is too acidic), which occurs when the kidneys lose ability to filter waste products from the bloodstream. Reduced phosphorous content compared with that in many maintenance diets. Dietary phosphorous is essential for cell structure/function and bone development in dogs and cats. However, in animals with kidney problems, phosphorous levels are often abnormally high. Phosphorus is believed to play a role in the progression of kidney problems in dogs and cats.