calcium

Question 1

what are the sources of calcium

Answer 1

-milk

-cheese

-leafy green vegetables

-yoghurt

Question 2

what is the recommended dietary allowance of calcium

Answer 2

children- 800mg

teenagers- 1,200mg

adults- 800mg

pregnancy and lactation- 1,200mg

Question 3

what are the biological functions of calcium

Answer 3

-aids the formation of strong bones and teeth

-assists blood clotting which is necessary if an injury causes damage to blood vessels

-aids normal muscle contraction

Question 4

what are the effects of deficiency of calcium

Answer 4

-rickets: a bone disease that affects children, causing their bones to become soft and weak. this can lead to an increased risk of fractures and bone deformities, e.g. bow legs

-osteomalacia: a bone disease that affects adults, causing their bones to become soft and weak due to low bone mass. this can lead to increased risk of fractures and bone pain

-osteoporosis: a bone disease in common in older people or post-menopausal women, causing their bones to become brittle and fragile due to a loss of bone mass. this can lead to an increased risk of fractures, stooped postures and back pain

-tooth decay: a condition where the tooth enamel, bone and cementum weaken, increasing the risk of dental decay

-slow blood clotting of ruptured blood vessels. this can cause haemorrhaging

-muscles fail to relax after contraction. this can cause muscular spasms, cramps and convulsions

Question 5

what are the factors that assist calcium absorption

Answer 5

-vitamin D stimulates the production of calcium-binding protein, assisting absorption

-the hormone oestrogen, produced in the ovaries, promotes calcium absorption

-phosphorus combines with calcium, creating calcium phosphate, which is easier to absorb

-an acid environment promotes calcium absorption. consuming foods high in vitamin C provides this

Question 6

what are the factors that hinder calcium absorption

Answer 6

-tannins present in tea and coffee bind to calcium, inhibiting absorption

-excess dietary fibre binds to calcium, inhibiting absorption

-excess fat binds with calcium, creating insoluble and non absorbable calcium soaps

-oxalic acid in rhubarb and spinach binds to calcium, inhibiting absorption