1.7 Minerals

Question 1

Important minerals include:

Answer 1

Calcium 
Iron 
Sodium
Potassium
Iodine
Zinc

Question 2

Calcium: Function

Answer 2

• combines with other minerals to form hard crystals that give your bones strength and structure

A small amount of calcium is absorbed into the blood to assist in:

• Normal blood clotting
• Transmission of impulses along nerves
• Contraction and relaxation of muscles

Question 3

Calcium: Sources

Answer 3

milk products, tofu, dark green vegetables.

Question 4

Calcium: Deficiency

Answer 4

Bones act like a calcium bank, if you do not take in enough calcium from your diet, the body will withdraw calcium from your ‘bone bank’ for use in other parts of the body.

Calcium absorbed in the intestines = calcium lost in urine

If calcium balance is not maintained, calcium from the skeleton is reabsorbed.

Bone loss will occur = osteoporosis

Question 5

Calcium: Osteoclasts

Answer 5

• break down the tissue in bonesand release theminerals, resulting in a transfer ofcalciumfrom bone tissue to theblood.

Question 6

Calcium: Recommended Daily Intake:

Answer 6

12-18 : 1.300 mg per day

19+ : 1000 mg per day

M over 50/ F over 70 - 1300 mg per day

Question 7

Iron: Function

Answer 7

Required for the formation of haemoglobin and myoglobin.

Haemoglobin = protein present in red blood cells, transports oxygen to all cells

Myoglobin = holds oxygen in muscles in preparation for physical exercise.

Question 8

Iron: Deficiency

Answer 8

Iron deficiency = most common nutrient deficiency in the world.

Decreased production of red blood cells

• Anaemia
• Chronic fatigue
• Decreased capacity to exercise

Question 9

Iron: Absorption

Answer 9

Haem iron - readily absorbed : meat and fish

Non-haem - no readily absorbed: plant foods
- high amounts can reduce iron absorption

Foods high in Vitamin C ^ absorption

Teat, coffee and milk limit iron absorption.

Question 10

Iron: Recommended Daily Intake (RDI)

Answer 10

Children and adolescents – 10-13mg/day

Males – 7mg/day

Question 11

Sodium: Functions/sources

Answer 11

• Controls fluids that enter and leave the body
• Helps to control muscle contraction and relaxation
• processed foods

Question 12

Sodium: Deficiency

Answer 12

High levels of physical activity in intense heat over extended periods of time

Rare:
Muscle cramps
Vomiting
Lethargic

Question 13

Sodium: Excess

Answer 13

• High blood pressure (hypertension)
• Fluid retention (odema)
• Kidney and heart failure
• Reduced absorption of calcium

Question 14

Sodium: RDI

Answer 14

7-12months – 320-580mg

4-7 years – 460-1730mg

8 years – adult
2300mg

Question 15

Potassium: Functions

Answer 15

• Works with sodium to maintain a balance of fluid
• Works with sodium to help control muscle contraction and relaxation
• Helps to achieve a steady heartbeat

Question 16

Potassium: Sources

Answer 16

Soya beans
Bananas
Most fruit and vegetables
Nuts

Question 17

Potassium: Deficiency

Answer 17

Weakness
Muscle cramps
Increased blood pressure
Irregular heartbeat

Question 18

Potassium: RDI

Answer 18

Infants
0-6months – 390-580mg
7-12months – 470-1370mg

Children
1-3years – 980-2730mg
4-7years – 1560-3900mg

8 years – adults
1950-5460mg

Question 19

Iodine: Function/Sources/Deficiency

Answer 19

Helps to regulate growth, development and metabolic rate

Sources: seafood, bread, dairy

Deficiency: weight gain, enlargment of the thyroid gland, mental and physical retardation of an infant.

Question 20

Zinc: Functions/Sources/Deficiency

Answer 20

• Supports the work of numerous proteins in the body
• Immune function
• Growth and development
• Manufacture of haem for haemoglobin

Sources: protein-rich - oysters, beef, legumes

Deficiency - growth retardation, delayed sexual maturity, hinders digestion and absorption.