Sodium is the main positive charged ion (cation) in the sea water where the first one celled organism developed, it still is in the fluid between our cells, the interstitial fluid, while inside the cells potassium is the main cation. This difference is maintained by pumps which needs energy to run. read more
The body tries to reduce the sodium by pissing it out; unfortunately the body can only excrete salt to a salinity less than sea water (about 1.2-1.3%) sea water on the other hand has about 3-4% of salt. hence you keep loosing water and keep gaining salt the more you drink. read more
Its concentration in the extracellular fluid is 0.7-1 mmol/l. Magnesium has the following roles in the body: 1) Structural function in bones (2/3 Mg in the body) 2) Cofactor of 300 enzymes. 3) Reduces neuromuscular excitability. Our average daily intake of Mg 2+ are just units of mmol (legumes, grains, vegetables, milk). read more
Sodium, or salt, has a bad reputation -- too much in your diet can cause high blood pressure, a risk factor for heart disease and kidney disease. However, sodium also plays a major role in your body's homeostasis, helping to control biological processes that keep you healthy. read more