Lecture 24: Minerals

Question 1

What is selenium?
What is its function?
Where is its sourced from?

Answer 1

Selenium is a TRACE element
Function = Is a COFACTOR for GPx(antioxidant) and IDI(which converts T4 to T3)
Sourced = fish, brazil nuts and liver
also sourced from poultry and eggs

Question 2

Selenium

• What is the required dose?
• What happens if your deficient?

Answer 2

Dose = 60-70 mirograms
- NZ has low levels of selenium in soil but we don’t have human selenium deficiency
= Keshan’s disease: enlargement of hear an loss of heart flexibility
- Animals are affected by selenium deficiency
= White muscle disease in sheep: stillborn or will die in the first few days, and unsteady gait and arched back —-> responds to selenium supplements

Question 3

Iodine

• What is its function?
• Where is it sourced from?
• What is the required dose?

Answer 3

Function: Needed for the production of thyroid hormones
Sourced: Seaweed, iodised salts
Dose: At least 100micrograms

Question 4

Iodine

- What happens when you are iodine deficient?

Answer 4

Goitre is the swelling of the thyroid gland in response to low iodine levels

• Less than 100 mg will result in hypothyroidism
• Less than 50mg will result in mental and physical retardation & goitre
• Less than 25mg will result in severe defects and abortions

Question 5

What are some of the reasons for the reduction in Iodine in NZ?

Answer 5

• lower intake of iodised salt

- Use of non-iodised salt - use of rock salt instead

Question 6

Iron

• what is the function of iron?
• where is it sourced from?
• what is the required dose?

Answer 6

Function: Transport oxygen around the body when it is used by haemoglobin - also assists many enzymes
Source: RED MEAT
Dose: 18mg for menstruating women, 8mg for men
- iron is absorbed better if the person is suffering from the lack of it - absorption is higher when status is low

Question 7

What inhibits iron intake?

What promotes iron intake?

Answer 7

INHIBITORS =  phylates, EDTA, coffee & tea, and other 2+ ions e.g calcium, zinc, manganese
PROMOTORS = vitamin C, meat & fish & protein taken at the same time as non-haem iron

Question 8

Zinc

• what is the function of zinc?
• where is it sourced from?
• what is the required dose?

Answer 8

Function: Many(300) proteins need zinc for functions and regulation.
Source: Oysters
Dose: 14mg for men and 8mg for women

Question 9

What inhibits zinc intake?

What promotes zinc intake?

Answer 9

INHIBITOR: Phylates and other 2+ ions

PROMOTOR: Animal proteins and organic acids

Question 10

What is since deficiency caused by?

What happens when you zinc deficient ?

Answer 10

Caused by: decreased intake, decreased bioavailability due to high intake of inhibitors and losses due to vomiting and diarrhoea
Deficient in zinc = stunted growth, decreased taste sensation, impaired immune function, dwarfism, delayed puberty and hypopigmentation of hair