Dear Linda: I don't know much about renal disease in infants. I do deal with a lot of adult renal patients who have kidney failure. If the phosphate is a problem, I would think that some type of phosphate binder could be used. I don't work in a children's hospital, so I am relatively unaware of all the formula products on the market for special diseases. I would think that regular formula would be higher in phosphorus than Human Milk. As for increasing sodium in the milk..... sodium is increased during the process of weaning. I don't think there is any way to increase the sodium in the milk other than this way. I would think that human milk would be the absolute very best for a baby with kidney problems. It is already low in protein, low in renal solute load, and highly digestible. One of the things one must always consider is that individuals with kidney problems receive sufficient non-protein calories to "spare" protein for growth and maintenance. Breaking down protein for energy will elevate the Blood Urea Nitrogen (BUN), thereby increasing the load on the kidney. I would think it would be very important to allow this baby to finish all the milk on one side before going to the other side so that the fat intake would be as high as possible. I'm sure there are others more qualified to comment than I, but these are the thoughts off the top of my head. Martha Brower RD LD IBCLC (more familiar with kidney disease than I want to be. I have seen a tripling of renal patients in my nutrition practice in the last 5 years! I have often wondered if we are starting to see the results of the ABM experiments of the 40s and 50s!!