RDI
Overdosing
Conception, pregnancy and breastfeeding
Food sources
Sodium (commonly known as salt or 'sodium chloride') is a 'major' mineral, and the main component of our blood and body fluids outside our cells. Sodium has a balancing relationship with
potassium in the body. Together they regulate the fluid, nutrient and waste product movement into and out of our cells. This relationship also enables our muscles and nerves to conduct the 'electric charges' that send our body messages for movement and functioning and contributes to our body's fluid balance. The kidneys regulate the level of sodium, water and potassium in the body.
When people eat foods high in salt, their thirst sensation is triggered. This is nature's way of keeping the sodium-water balance in the body at its desired level.
Diets very rarely lack sodium. However, low sodium levels can occur with vomiting and diarrhoea, or heavy sweating with excessive exercise. In these cases water is also lost and dehydration becomes an issue. If a person takes salt tablets to increase their salt, they are likely to worsen their dehydration, but if only water is consumed and salt is not replaced, the person can develop 'hyponatraemia' or low sodium in the blood. This is why athletes consume drinks with water, glucose and salt, to help restore their sodium balance and combat dehydration.
A sodium deficiency may lead to muscle cramps, apathy and loss of appetite.
Recommended Daily Intake (RDI) is about 40-100mmol. Most people eat more than an adequate amount of salt and it is generally advised to limit foods with a high salt content.
Overdosing. Excessive intakes of sodium can contribute to fluid retention and temporary high blood pressure. Poor kidney function can also contribute to sodium toxicity. However, this toxicity may not be an issue if the body's water needs are met.