Vitamins

Question 1

fat soluble

Answer 1

A (retinol, beta carotene)
D (cholecalciferol, ergocalciferol)
E (tocopherol)
K (naphthoquinone)

Question 2

water soluble

Answer 2

C (ascorbic acid)
B Group:
B1 (thiamine)
B2 (riboflavin)
B6 (pyrodoxine)
B12 (cobalamin)
folic acid
niacin

Question 3

forms of vitamin A

Answer 3

retinol (pure vit A)
-animal sources
eg fish, fish oils, butter

beta carotene
-brightly coloured fruit and veg
eg carrots, apricots, tomatoes

Question 4

functions of vit A

Answer 4

• produces rhodopsin to aid night vision
• essential for lining membranes
• aids growth and repair of cells
• healthy hair and skin (antioxidant)

Question 5

effects of vit A deficiency

Answer 5

• night blindness
• xerophthalmia (dry eyes)
• stunted growth in children
• dry mucous membranes - rough and dry skin

Question 6

vit A RDA

Answer 6

children - 400-500mcg
adolescents - 600-700mcg
adults - 600-700mcg
pregnancy/lactation - 950mcg

Question 7

properties of vitamin A

Answer 7

retinol

• yellow fat soluble alcohol
• insoluble in water
• heat stable
• reduced by dehydration

beta carotene

• bright orange or yellow oil
• insoluble in water
• heat stable
• sensitive to dehyration

Question 8

hypervitaminosis - excess vit A

Answer 8

causes-
dry skin
enlarged liver
fatigue
hair loss
risk of birth defects and miscarriage
death

Question 9

types of vitamin D

Answer 9

cholecalciferol
from sunlight or food eg oily fish
-sunlight converts 7 dehydrocholesterol in the skin to cholecalciferol

ergocalciferol
from fungi or yeast
-action of the sun converts ergosterol to ergocalciferol

Question 10

functions of vitamin D

Answer 10

strong bones and teeth
aids absorption of calcium and phosphorous
prevents rickets and osteoporosis
regulates blood calcium levels

Question 11

effects of vit D deficiency

Answer 11

rickets in children
osteomalacia
osteoporosis
dental decay

Question 12

vit D RDA

Answer 12

children - 10mcg
adolescents - 15 mcg
adults - 10 mcg
pregnancy/lactation - 10 mcg

Question 13

properties of vit D

Answer 13

white crystalline solid
fat soluble
insoluble in water
stable to heat
stable to acids, alkalis and oxygen

Question 14

hypervitaminosis - excess vit D

Answer 14

more common among young children than adults due to high concentration of calcium in the blood

symptoms-
nausea
mental confusion
vomiting and thirst
loss of bone mass

Question 15

vit E sources and deficiency

Answer 15

margarine, egg yolk, spinach, pulses

rare for the majority of the population

Question 16

functions of vit E

Answer 16

• acts as an antioxidant
• destroys free radicals -reduces effects of aging
• protects healthy blood cells from damage
• strengthens immune system
• helps ease pre-menstrual tension

Question 17

properties of vit E

Answer 17

fat soluble antioxidant
insoluble in water
delays rancidity and oxidation
damaged by alkalis, oxygen and light
heat stable, stable in acids

Question 18

vit K sources

Answer 18

plant: green veg, cereals
animal: meat, liver, eggs
body: made by bacteria in the gut

Question 19

functions of vit K

Answer 19

• for synthesis of prothrombin, essential for clotting blood

- regulates calcium balance in bones

Question 20

effects of deficiency in vit K

Answer 20

delayed clotting of blood

Question 21

vit C functions

Answer 21

antioxidant, prevents CHD and some cancer
helps white cells fight infections - strong immune system
essential for collagen formation
strong bones and teeth
essential for absorption of non haem iron

Question 22

effects of a deficiency in vit C

Answer 22

scurvy in severe cases
anemia
slower healing of cuts and wounds
bruising and bleeding due to weaker blood vessels and tissues

Question 23

RDA of vit C

Answer 23

children: 45mg
adolescents:60mg
adults:60mg
pregnancy/lactation:80mg

Question 24

properties of vit C

Answer 24

white crystalline acid with sharp flavour
destroyed by alkalis, dry/moist heat and enzymes
acts as an antioxidant
affected by metals eg copper, iron

Question 25

folic acid sources

Answer 25

fortified foods
wholegrain cereals
leafy green veg
offal

Question 26

functions of folic acid

Answer 26

essential for manufacture of DNA & RNA
protects against neural tube defects eg spina bifida
assists B12 in the formation of red blood cells
assists protein metabolism

Question 27

effects of a deficiency in folic acid

Answer 27

tiredness and fatigue
anaemia in young children/pregnant women
risk of neural tube defects in foetus