Chapter 12: Fat-soluble vitamins Flashcards
What are the 2 classes of vitamins?
1) water soluble
2) fat soluble
Examples of water-soluble vitamins
Vitamin B complex and C
Examples of fat-soluble vitamins
Vitamins A, D, E, and K
How much of fat-soluble vitamins are absorbed?
40-90%
How much of water-soluble vitamins are absorbed?
90+%
Where does the digestive process start for ALL vitamins?
The stomach, the release of vitamins from food occurs
What aids the stomach in release of ALL vitamins from food?
Digestive enzymes produced by the pancreas
Where are ALL vitamins absorbed?
Small intestine
What aids the small intestine in fat-soluble vitamin absorption?
Bile produced in the liver (stored in gall bladder)
What else is absorbed during fat-soluble vitamin digestion?
dietary fat (along with the vitamins) are carried by the chylomicrons into the lymphatic circulations
Where in the body is vitamin K produced?
Made by bacteria in the ileum of the small intestine and large intestine
What is the transport of vitamins based on?
Solubility
How are water soluble vitamins transported?
Into the portal vein
Where are fat-soluble vitamins stored in the body?
In fat (adipose of liver)
Are water soluble vitamins stored?
It is very limited except for B-6 and B12
What vitamins can be toxic in very high doses?
A and D
What are retinoids?
active form of vit A
3 forms of retinoids:
Retinal, retinol, and retinoic acid
Dietary sources of retinoids:
liver, fish oils, fortified dairy products and eggs
What are caroteinoids?
Provitamins which can be converted to Vit A
Most common caroteinoid?
Beta-carotene
Dietary sources of caroteinoids:
dark green and yellow-orange vegetables and fruit
Where is most vitamin A stored in your body?
liver ~90%
Which has lower absorption: carotenoids or retinoids?
carotenoid
