Fat soluble vitamins Flashcards
describe the process of digestion/absorption of fat-soluable vitamins?
- get absorbed into micelle whole
- micelle travels into enterocyte and becomes a chylomicron
- the chlyomicron gets absorbed into the lacteal and into the lymphatic system
- gets escorted by dietary fat
what are provitamins?
a vitamin precursor that is converted to the vitamin in the body
what is a preformed vitamin
the complete form of a vitamin
what is hypervitaminosis?
vitamin toxicity
what is considered a mega-dose?
10x the DRI for something
what is fortfication?
added vitamins and minerals that are not naturally present/present at that level in a food
what is enrichment?
a form of fortification where vitamins are added back into refined foods to bring it back to the “natural composition”
what is bioavaliability?
the degree to which a nutrient is absorbed from food and used by the body
true/false: fat soluable vitamins are more likely to be bioavaliable compared to water soluable vitamins?
false - fat soluable vitamins are less likely to be bioavaliable compared to water soluable vitamins
what are antioxidants?
compounds that neutralize free radicals
what are the fat soluable vitamins?
- vitamin A
- vitamin D
- vitamin E
- vitamin K
what are the different forms of vitamin A?
retinoids (preformed vitamin A) and carotenoids (provitamin A)
what are the differnet forms of retinoids?
- retinol
- retinal
- retinoic acid
what are the different forms of carotenoids?
- alpha-carotene
- beta-carotene
- beta-cryptoxanthin
what is the form of vitamin A that is found in the liver?
retinyl ester
what are the functions of vitamin A?
- vision
- reproduction - necessary for sperm cell development
- immunity - decreased risk of infectious disease
- cell growth and developement
- increased bone health
what is the recommended intake for vitamin A?
- males = 900 micrograms
- females = 700 micrograms
what are the symptoms/conditions associated with vitamin A toxicity
- non-threatening carotenodermia = skin turns yellow
- liver damage
- increased risk of birth defects
- increased risk of osteoporosis
what are the symptoms/conditions associated with vitamin A deficiency?
- night blindess
- xerophtalmia = dryness and permanent damage to the cornea of the eye
- keratinazation = cells become keratinized (hard) and are unable to produce mucus
- increased risk of infection
what is the family name for vitamin D?
calciferol
what are the two forms of vitamin D?
- ergocalciferol (vitamin D2)
- cholecalciferol (vitamin D3)
vitamin D activation occurs in the ____
liver and kidneys
what are the functions of vitamin D?
- maintaining bone mass
- aiding in the absorption of calcium
what are the symptoms/conditions of vitamin D deficiency?
- increased cancer incidence
- increased insulin resistance
- decreased blood pressure regulation
- issues with bone health and bone density
what is rickets?
bowed legs in children; bones are inadequately mineralized
what is osteomalacia?
bowed legs in adult; bones are inadequately mineralized
what is the RDA for vitamin D
600-800 IU (adults)
what is considered vitamin D toxicity?
4,000 IU
what are the symptoms/conditions associated with vitamin D toxicity?
- loss of appetite
- nausea
- vomiting
- constipation
- loss of bone calcium due to overabsorption
where is vitamin D stored?
in the adipocytes
what are the functions of vitamin E?
- antioxidant - prevents LDL oxidation
- cell membrane health - donates electron to neutralize free radicals at cell membrane
- decreases stickiness of blood vessels
- anticoagulant
what is the UL for vitamin E?
1000 milligrams
what are the symptoms/conditions associated with vitamin E deficiency?
- nerve and muscle weakness
- cell membrane damage
describe the connection between vitamin A and vision?
- rhodopsin (rods) and iodopsin (cones) are proteins that turn light into visual images
*these proteins cannot function without vitamin A - light hits the retinal cell changing its shape, which causes the protein to detach (bleaching)
- when bleaching occurs a signal is sent to the optic nerve
what are the two forms of vitamin K?
- phylloquinone (vitamin K1) and menaquinone (vitamin K2)
what is the function of vitamin K
coagulation (blood clotting)
what is the DRI for vitamin K?
- AI: 90-120 micrograms/day
what is the difference betwen the two forms of vitamin K?
- vitamin K1 (phylloquinone) is provided through plant based foods
- vitamin K2 (menaquinone) is produced by colonic bacteria
what are some food sources of vitamin A?
- milk
- eggs
- cheese
- organ meat (liver)
- cereals
what are some food sources of provitamin A?
- carrots
- sweet potatoes
- spinach
what are some food sources of vitamin D?
- fortified dairy
- breakfast cereals
- fatty fish
what are some food sources of vitamin E?
- vegetable oils
- nuts and seeds
- avocados
what are some food sources of vitamin K?
- leafy greens
- green cabbage
- brussel sprouts
