fat soluble vitamins Flashcards
retinol (pure vitamin A)- properties
easily absorbed, stored in the liver yellow, fat soluble alcohol insoluble in water soluble in organic solvents heat stable but affected by prolonged high temperatures destroyed by oxygen
retinol sources
fish liver oils milk seeds eggs cheese offal butter margarine oily fish
functions of vitamin a
- needed to make pigment rhodopsin in the retina which helps eyes adapt to dim light
- helps maintain healthy skin and mucous lining
- aids growth and development of children
- acts as a powerful antioxidant that can counteract the damaging effects of free radicals
beta carotene (pro vitamin a)
not easily absorbed , converted to retinol in the lining of the intestine
properties of beta carotene (pro vitamin a)
yellow, or orange fat soluble oil insoluble in water soluble in fat solvents heat stable unaffected by oxygen a powerful antioxidant that has the ability to counteract the damaging effects of free radicals
sources of beta carotene
carrots tomatoes peppers leafy green vegetables
sweet potatoes apricots
effects of vitamin a deficiency
night blindeness
stunted or delayed growth in children
risk of damage to cells by free radicals increasing risk of stroke, cancer and coronary heart disease
follicular hyperkeratosis-rough dry and inflamed skin
xerophthalmia- can occur on surface of eye due to lack of mucous , causes eyes to dry out and become infected- can eventually lead to blindness
cholecalciferol D3
animal form of vitamin d formed when UV light shines on the skin converting 7-dehydrocholesterol in the epidermis to cholecalciferol
ergocalciferol D2
plant form of vitamin d created when UV light shines on fungi and yeast converting ergosterol into ergo calciferol
properties of vitamin d
most stable of all vitamins fat soluble insoluble in water heat stable- unaffected by cooking or preservation methods unaffected by acids alkalis and oxygen
food and other sources of vitamin d
oily fish fortified milk eggs butter margarine fish liver oils sunlight
functions of vit d
controls absorption of calcium and phosphorus into the blood
regulates the amount of calcium and phosphorus in bones and teeth helping to maintain density and strength
regulates calcium levels in the blood, if too low it stimulates the production of a calcium binding preotein needed to absorb more calcium
effects of vit d deficiency
increased risk of bone diseases such as osteomalacia, rickets and osteoporosis
increaded risk of bone diseases and tooth decay
rda of calcium
children, adults etc 10 micrograms
adolescents 15 micrograms
rickets
bone disease that affects children causing their bones to become soft and weak
increased risk of fractures and bone deformities
osteomalacia
bone disease that affects adults causing their bones to become soft and weak due to low bone mass- increased risk of bone factures and bine pain
osteoporosis
bone disease that is common in older people and post menopausal women causing their bones to become brittle and fragile due to a loss in bone mass- increased risk of fractures, stooped posture, bck pain and collapsed vertebra
tooth decay
condition where the tooth enamel, bone and cementum weaken increasing risk of dental decay
vitamin e scientific name
tocopherol
properties of vit e
fat soluble incoluble in water unstable to light and alkalis antioxidant stable to acids heat stable
sources of vitamin e
gums wheat germ seeds avocados eggs vegetable oils
functions of vitamin e
powerful antioxidant that can counteract the damaging effects of free radicals
protects red and white blood cells from damage
protects the retina in the eyes of newborn babies
effects of vitamin e deficiency
risk of damage to cells by free radicals- increasing risk of cancer, stroke and chd
anaemia due to low levels of red blood cells which are needed to transport oxygen
reduced immunity due to low levels of white blood cells which are needed to fight infection
eye disorders in premature babies which can lead to blindness
forms of vitamin k
phylloquinone K1- made by plants
menanquinone k2- made by intestinal bacteria
menadione k3- a synthetic form
