Sodium

Question 1

Where is Sodium absorbed and how efficient is it?

Answer 1

Sodium is absorbed in the small intestine and is 98% efficient

Question 2

How is Sodium transported through the body?

Answer 2

Sodium is transported by the sodium/potassium pump

Question 3

How is Sodium excreted from the body?

Answer 3

Majority is excreted through urine, or during excessive sweating
Small amounts lost in faeces

The amount excreted depends on ethnicity

The body can conserve amounts by reducing urine output

Question 4

What are the functions of Sodium?

Answer 4

The main role of sodium is the maintenance of extracellular fluid volume (including plasma and interstitial fluid)
95% of the body’s sodium is kept in the ECF by the Na/K ATP-ase pumps

Sodium also assists with uptake of glucose and amino acids in the small intestine

Assists with normal muscle and nerve function

Maintains membrane potential of cells

Question 5

What is the AI for Sodium?

Answer 5

For both men and women it is 460-920mg

But only 200mg is required for normal physiological function

Question 6

Explain Sodium as a component of salt

Answer 6

Sodium makes up 39.3% of table salt (NaCl)

To find the amount of sodium in salt times the quantity by 0.393

Nutrition labels in Australia indicate sodium content not salt content

Question 7

What is caused by a deficiency of Sodium?

Answer 7

Hyponatremia

• headaches
• nausea
• vomiting
• muscle cramps
• fatigue
• disorientation
• coma if left untreated

Occurs when losses exceed intake (excessive sweating, vomiting, diarrhoea)

Question 8

What occurs with sodium toxicity?

Answer 8

Hypernatremia due to excessive water loss

• low blood pressure
• fainting
• convulsions

Question 9

Where is salt consumed in the diet?

Answer 9

77% from processed and restaurant foods

12% naturally occurring

5% added in home cooking

6% added to the plate