Sodium is an essential mineral. It is the most abundant cation in the extracellular fluid, and strongly affects the distribution of water between intracellular and extracellular compartments by osmosis. It functions in nerve conduction and is part of the bicarbonate buffer system.
It is excreted in urine and perspiration. Normal intake of sodium chloride occurs via table salts and as a constituent of the vast majority of dietary intake. Information about the sodium content of common foods is provided.