It contains sodium of course, but it contains over 80 different minerals that are all essntial for normal body function. In my experience with salt+water consumption I have had no problems with kidneys or blood preasure. Same goes for my wife who is also consuming salt. (We are both 30 years old)

Another thing I would like to add is that I often donate blood or plasma and every time when they run a blood test they tell me that I am the perfect doner, due to the resaults they see.