micronutrients Flashcards
what are vitamins?
- nutrients required in small amounts
- for variety of processes
- most can’t be made by body so in diet
- fat-soluble
- water-soluble
what are the fat-soluble vitamins?
- stored in body
- A,D,E,K
what are the water-soluble vitamins?
- can’t be stored in body
- required daily
- B,C
what is vitamin A needed for?
- fat-soluble
- normal iron metabolism
- normal skin and vision mainenance
- normal function of immune system
what and where are two forms of vitamin A obtained?
- readymade as retinol from animal sources
- beta carotene from plant sources
what is vitamin A concentration expressed as?
- retinol equivalents (RE)
what does the body do to some carotenoids?
- convert to retinol
where is vitamin A found?
- pre-formed in liver
- whole milk
- produced from beta-carotene provided by dark, leafy veg, carrots and orange coloured fruit
what does UK law state about fortification?
- margarine must be fortified with vitamin A and D
what are the consequences of vitamin A deficiency?
- night blindness
- eye ulceration causing blindness
what are the consequences of large intakes of vitamin A?
- toxic
- liver and bone damage
what are pregnant women advised about vitamin A?
- don’t eat liver/pate
- high levels retinol may be present
- excess leads to birth defects
what is vitamin D needed for?
- fat-soluble
- absorption and use of calcium/phosphorous
- blood calcium levels
- normal bones,teeth,muscle function maintenance
- normal function of immune system
what are the two forms of vitamin D?
how is it obtained?
how much required?
- D2 and D3
- action of sunlight
- small amounts measured in micrograms
what are two sources of vitamin D?
- oily fish
- meat
- eggs
- fortified cereals and spreads
how is vitamin D obtained?
- synthesis in skin following sunlight
what are the consequences of vitamin D?
- rickets in children
- osteomalacia in adults
- increased falls in elderly
what is vitamin E needed for?
- fat-soluble
- antioxidant
- protect cells against oxidative damage
what are sources of vitamin E?
why is it naturally present in them?
- large amount of polyunsaturated fats: plant oils, nuts, seeds
- prevents oxidation
what is vitamin K needed for?
- fat-soluble
- blood clotting
- normal bone maintenance
what are sources of vitamin K?
where is it naturally produced in the body?
- green leafy veg
- meat
- dairy products
- eggs
- produced in gut by bacteria
what do they do to new-borns with vitamin K?
- injection
what is Thiamin (B1) needed for?
- water-soluble
- energy release from carbs
- normal function of nervous sytem and heart
what are the sources of Thiamin (B1)?
- whole grains
- nuts
- meat
- milk
- veg
- fortified cereal
what are the consequences of thaimin deficiency?
- nervous sytem disease:beriberi
what is Riboflavin (B2) needed for?
- water-soluble
- energy release of protein/carbs/fats
- norml function of nervous system
- skin maintenance
- healthy rbc
whar are sources of Riboflavin (B2)?
- milk
- eggs
- rice
- fortified cereals
- liver
- green veg
what is Niacin (B3) needed for?
- water-soluble
- energy release from food
- normla function of nervous sytem
- psychological function
- skin maintenance
what are sources of Niacin (B3)?
- meat
- eggs
- dairy products
- yeast
what are the consequences of Niacin deficiency?
- sun-sensitive skin (pellagra)
- rare for UK and western countries
what is vitamin B6 needed for?
- cysteine synthesis
- energy-yielding metabolism
- nervous system and hormonal function
- psychological
what other vitamins does vitamin B6 work with to maintaon normal blood homocysteine levels?
- folate
- vitamin B12
who is at risk of vitamin B6 deficiency?
- prolonged administration of certain drugs
what other vitamin does B6 work with to maintain normal blood homocysteine levels?
- folate
- vitamin B12
what are sources of B6?
- milk
- eggs
- whole grains
what is vitamin B12 needed for?
- normal function of immune system
- nervous system
- formation of rbc
what are sources of vitamin B12?
- meat
- fishmilk
- cheese
- eggs
who is at risk of vitamin B12 deficiency and what are the consequences?
- strict vegans
- peripheral nerve damage develops
what is folate needed for?
- normal rbc
- normal cell division
- normal psychological function
what are sources of folate?
- green leafy veg
- oranges
- bananas
who is most at risk of low folate levels?
- teen girls
- elderly
what are the consequences of folate deficiency?
- neural tube defects in new borns
- immature rbc cause megaloblastic anaemia
how is folic acid linked to folate?
- synthetic form used in supplements
- food fortification
what is vitamin C needed for?
- immune system
- strong teeth and bones
- skin
- absorption of iron
what are sources of vitamin C?
- citrus fruits
- green veg
- tomatoes
what are the consequences of vitmain C deficiency?
- bleeding gums
- fatigue
- aching joints and muscles
what are minerals?
- inorganic substances
- small different amounts for each
- trace elements = small amount
what mineral does the body contain the most of?
what is it needed for?
- calcium
- strong bones and teeth
- normal blood clotting
- nervous system function
what are sources of calcium?
- dairy
- green leafy veg
- fortified bread
how much calcium does skeleton contain?
- 99%
what regulates calcium level in the blood?
- vitamin D
what are the consequences of low calcium intake?
who is most likely at risk?
- withdrawn from bones
- low bone density
- teen girls
what does low vitamin D AND calcium cause?
- osteoporosis
what is phosphorous needed for?
- strong bones and teeth
- energy production
- cell membrane function
what are sources of phosphorous?
- red meats
- fish
- dairy
what is iron needed for?
- formation of haemoghlobin
- oxygen transportation
- energy production
what are sources of iron?
- meat
- eggs
- fish
what is the source of haem iron?
- animal sources
what is the source of non-haem iron?
how is it absorbed?
- plant sources
- vitamin C helps absorbtion when eaten at the same time
what amounts of iron is required?
- teen girls and pregnant women need more than men
- 1/2 teen girls in uk low intake
what are the consequences of low iron?
- anaemia
