vitamin D

Question 1

what are the forms of vitamin D

Answer 1

-cholecalciferol D3: an animal form of vitamin D, created when UV light shines on the skin.

ergocalciferol D2: a plant form of vitamin D, created when UV light shines on fungi and yeasts.

Question 2

what are the properties of vitamin D

Answer 2

-most stable of all vitamins

-fat soluble/insoluble in water

-heat stable: unaffected by cooking or preservation methods

-unaffected by acid, alkalis and oxygen

Question 3

what are the sources of vitamin D

Answer 3

-oily fish

-margarine

-eggs

-butter

-sunlight

Question 4

what are the biological functions of vitamin D

Answer 4

-controls the absorption of calcium and phosphorus into the blood

-regulates the amount of calcium and phosphorus in the bones and teeth, helping to maintain density and strength

-regulates calcium levels in the blood; if blood-calcium levels are too low, it stimulates the production of a calcium-binding protein needed to absorb more calcium

Question 5

what are the vitamin D defciency diseases

Answer 5

-rickets: a bone disease that affects children, causing their bones to become soft and weak. this can lead to 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, can lead to risk of fractures and bone pain

-osteoporosis: a bone disease common in older people or post-menopausal women, causing their bones to become brittle and fragile due to a loss of bone mass, can cause increased risk of fractures, stopped posture and back pain

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

Question 6

what is the recommended dietary allowance of vitamin D

Answer 6

children and adults: 10

teenagers: 15

Question 7

what is hypervitaminosis

Answer 7

fat soluble vitamins are stored in the liver for several months. if a diet contains an excessive intake of vitamin D or A they build up in the liver to toxic levels, leading to harmful condition called hypervitaminosis. this condition is more likely to occur in people who overuse dietary supplements, such as cod liver.

Question 8

what are the symptoms of hypervitaminosis A

Answer 8

-miscarriage

-birth defects

-bone pain

-enlarged liver

Question 9

what are the symptoms of hypervitaminosis D

Answer 9

-vomiting

-kidney damage

-weight loss

-can lead to death