Those vitamin drops just foul the water/food. Unless prescribed by a vet they are a waste IMO.

The main thing to do is cut out sugary foods from the diet. This means no corn, peas, carrots, fruits or store bought treats. Then try and get some pedialyte(sp?) and 50/50 the water it will help keep them hydrated and help them not need to drink so much which will also cut down the urine back to normal. But yes high-protien foods are needed like hamsterhaven said hard boiled egg, tofu, chicken, soy milk, and other such things.

<3