Principal sources and dietary importance of calcium and iron

Question 1

Calcium (Principal sources)

Answer 1

Sources of calcium are milk, cheese, small fish eaten with bones, cereals, soya beans and vegetable

Question 2

Calcium (Dietary importance)

Answer 2

Vitamin D is required in the absorption of calcium from the intestine

• Calcium, in the form of calcium phosphate, is deposited in the bones and teeth and makes them hard
• It is present in the blood plasma and plays an essential role in normal blood clothing
• Needed for chemical changes which make muscles contract and for the transmission of nerve impulses.

Question 3

Iron (Principal sources)

Answer 3

Sources of iron include liver, kidney, red meat, egg-yolk, bread and green vegetables

Question 4

Iron (Dietary importance)

Answer 4

• The red blood cells contain the pigment haemoglobin. Part of the haemoglobin molecules contains iron and plays and important role in carrying oxygen around the body
• Iron is a structural component of myoglobin which is a protein in muscle cells which stores oxygen
• Iron is needed in the muscles and for enzyme systems in all body cells