Fat Soluble Vitamins Flashcards
(44 cards)
Vitamins
-an organic compound required as a nutrient in tiny amounts by an organism
Vitamins cannot be synthesized in sufficient quantities by an organism, and
must be obtained from the diet
Name 4 functions of vitamins
- hormone like functions as regulators of mineral metabolism (vit.D)
- regulators of cell and tissue growth and differentiation (some forms of vit. A)
- antioxidants (vit. E, C)
- enzyme cofactors (tightly bound to enzyme as a part of prosthetic group, coenzymes)
How are vitamins classified?
fat soluble and water soluble
What are fat-soluble vitamins?
hydrophobic compounds, absorbed efficiently with lipids
Fat-soluble vitamins function
transport in the blood in lipoproteins more likely to accumulate in the body
Examples of fat soluble vitamins
A, D, E, and K
Where are fat soluble vitamins stored? How long are they stored for?
- stored in the liver and adipose tissues
- fat soluble vitamins except for vitamin K, are stored for long periods of time
Toxic levels of fat soluble vitamins lead to
hypervitaminosis
Water soluble vitamins are
8 B vitamins and vitamin C
Water soluble vitamins
function
function as enzyme cofactors
Hydrophilic compounds dissolve …………….
easily in water
Water soluble vitamins are:
- not readily stored, excreted from the body
- their consistent daily intake is important
Many types of water-soluble vitamins are synthesized by
bacteria
Vitamin A is also called
Biologically active forms are:
retinol
retinoids: retinol, retinal, retinoic acid
Major vitamin A precursors (provitamins) are
plants carotenoids
Food originating from animals contain vitamin A in the form of
esters-retinol and long fatty acid
Vitamin A in foods:
retinyl esters (in animal food) beta-carotene (in plant food)
Vitamin A in the body
retinol (supports reproduction)
retinal (participates in vision)
retinoic acid (regulates growth)
Functions of vitamin A include
- vision
- immune function
- bone metabolism
- haematopoieis
- skin health
Vitamin A can be found from certain foods such as
egg yolk whole milk butter carrots squash meat fish
Vitamin A deficiency and toxicity
night blindness
blindness
hypovitaminoisis A
Vitamin D is also known as
calciferol, 1,25-dihydroxy
vitamin D3 or cholecalciferol (in animals)
vitamin D2 or ergocalciferol (in plants)
Vitamin D is a nonessential nutrient that acts
like a hormone in the body