potassium and sodium

An article about potassium and sodium's effects on our health-particularly interesting to me because I am curious about kidney function for two reasons. 1. My pre-eclampsia/toxemia during my pregnancy with Leanna(and I'm curious why I had an a-typical form of it) and 2. both my Dad and my maternal grandmother had kidney problems, and my grandmother's kidney problems began with her first pregnancy when she had preecalmpsia.
Also, I didn't know calcium was affected by your salt intake as well.
Just stringing together a few parts from the article(for the whole thing, go here)
Potassium and sodium together play a huge role in regulating blood pressure, and mounting evidence shows they are intimately involved in bone health. Molecular pumps that pull potassium into cells and push sodium out create a chemical battery that drives the transmission of signals along nerves and powers the contraction of muscles. Potassium and sodium help the kidneys work properly. They are important for energy production and fluid balance. Most of the focus on sodium and potassium centers on their effects on the kidneys, blood vessels, and heart. But these minerals affect every part of the body, including the relentless breakdown and buildup of bone. A diet high in sodium increases the amount of calcium excreted in the urine. This loss is especially prominent when calcium intake is low, as it is for so many Americans.