- sodium
- n.a mineral element and an important constituent of the human body (average sodium content of the adult body is 4000 mmol). Sodium controls the volume of extracellular fluid in the body and maintains the acid-base balance. It also helps maintain electrical potentials in the nervous system and is thus necessary for the functioning of nerves and muscles. Sodium is contained in most foods and is well absorbed, the average daily intake in the UK being 200 mmol. The amount of sodium in the body is controlled by the kidneys. An excess of sodium leads to the condition of hypernatraemia, which often results in oedema. This may develop in infants fed on bottled milk, which has a much higher sodium content than human milk. Since babies are less able to remove sodium from the body than adults the feeding of a high-sodium diet to babies is dangerous and may lead to dehydration. Sodium is also implicated in hypertension: a high-sodium diet is thought to increase the risk of hypertension in later life. Symbol: Na.
The new mediacal dictionary. 2014.