Well I wouldn't worry too much, but you are taking a methylated product so if it worries you that much I would probably just call the doctor and ask if its normal. Most of the time they won't answer questions over the phone cause they want your money so you may have to go to see the doc. I would not worry about it unless it keeps being cloudy for the next couple days. Then you can probably be sure its not something you as long as your diet is consistant. Just try to think hard if you ate something out of the norm and watch for it to continue. If it continues just got have it checked out. Better to be safe then sorry. Just from what I have heard though usually if your kidneys are going bad you have really foamy piss. I dont think that is refering to bubbles cause that is bound to happen when you trap air in the water. I have always heard it referred to as a "foam".