Chapter 13 - Fat Soluble Vitamins Flashcards
Vitamin
Compound needed in very small amounts in the diet to help regulate and support chemical reactions in the body
Fat Soluble Vitamin
Vitamin that dissolves in fat and such substances as ether and benzene, but not readily in water; vitamins A, D, E, K
Can vitamins be synthesized in the body, or are they synthesized in adequate amounts?
nope
Health _________ when vitamins aren’t consumed
declines
Vitamins are supplied by both _______ and ________ sources
animal ; plant
Vitamins are absorbed with what?
dietary fat
The adequate absorption of vitamins depends on…
efficient use of bile and pancreatic lipase.
Vitamin Digestion & Absorption in the Stomach
Digestive processes in the stomach begin the release of vitamins from food
Vitamin Digestion & Absorption in the Pancreas
Digestive enzymes produced by the pancreas aid in the release of vitamins from food
Fat Soluble Vitamin Digestion & Absorption in the Liver
Bile produced in the liver (and stored in the gallbladder) aid in fat-soluble vitamin absorption
Fat Soluble Vitamin Digestion & Absorption in the Small Intestine
Fat soluble vitamins are absorbed in the small intestine, along with dietary fat, and carried by cholymicrons into the lymphatic circulation
______________ is made in small amounts by bacteria in the ileum of the small intestine and in the large intestine
Vitamin K
Vitamin A and D are potentially toxic when you consume ___ to ___ times the DRI
5 to 10
All vitamins except which one are excreted quickly?
Vitamin K
Limited body stores of vitamins makes it easier to develop __________
deficiencies
Retinoid
Biologically active forms of Vitamin A, including retinol, retinal, and retinoic acid
Carotenoid
Pigmented materials in fruits and vegetables that range in color from yellow to orange to red.
3 types yield vitamin A activity in humans and thus are called provitamin A.
Many have antioxidant properties.
What are the 3 types of carotenoids that yield vitamin A activity?
alpha-carotene, beta-carotene, and beta-cryptoxanthin
Provitamin
Substance that can be made into a vitamin
Retinoids are commonly found in what foods?
liver fish fish oils fortified milk eggs
Provitamin A carotenoids are commonly found in what foods?
dark green/yellow orange fruits and vegetables
In the US, what percent of dietary vitamin A comes from animals?
70%
What is the most biologically active form of provitamin A?
beta-carotene
How is vitamin A measured?
retinol activity equivalents (RAE)
1 RAE is the equivalent of…
a) how much retinol?
b) how much beta-carotene?
c) how much of the other carotenoids?
a) 1 ug retinol
b) 12 ug beta-carotene
c) 24 ug other
What is the RDA for vitamin A?
900 ug RAE for men, 700 ug RAE for women
More than 90% of vitamin A body stores are in the _______, but they can also be stored where?
liver ; adipose tissue, kidneys, bone marrow, testicles, eyes
Vitamin A is excreted in _____ while carotenoids are excreted in _______
urine ; feces
What are the key functions of vitamin A?
- growth and development
- cell differentiation
- vision
- immune function
Retinoic acid is key in the production, structure, and function of….
epithelial tissue in the lungs, trachea, skin, and GI tract
Opsin
Protein of the rods of the retina that binds to 11-cis-retinal to form the visual pigment rhodopsin
Rhodopsin
Photoreceptor in rod cells composed of 11-cis-retinal and opsin
Bleaching Process
Process by which light depletes the rhodopsin concentration in the eye by separating opsin from the all-trans-retinal. This fall in the rhodopsin concentration allows the eye to adapt to bright lights
Dark Adaptation
Process by which the rhodopsin concentration in the eye increases in dark conditions, allowing improved vision in the dark
Epithelium
Covering of internal and external surfaces of the body, such as the lungs, GI tract, blood vessel linings, and skin
Psoriasis
Immune system disorder that causes a chronic inflammatory skin condition (painful patches of red, scaly skin)
Macular Degeneration
chronic eye disease that occurs when the tissue in the macula deteriorates, which causes a blind spot or blurred vision in the center of the visual field
What is the leading cause of nonaccidental blindness worldwide?
Vitamin A deficiency
Conjuctiva
Mucous membrane covering the front surface of the eye and lining of the eyelid
Keratomalacia
Softening of the cornea
Xerophthalmia
Condition marked by dryness of the cornea and eye membranes resulting from vitamin A deficiency. Can lead to blindness.
Follicular Hyperkeratosis
Condition in which keratin, a protein, accumulates around hair follicles.
What is the UL for retinol?
3000 mg/day
Vitamin D can be called a ________ vitamin
conditional
Prohormone
Precursor to a hormone
Vitamin D is commonly found in what foods?
fatty fish
cod liver oil
fortified milk
fortified breakfast cereals
Previtamin D3
Precursor of 1 form of vitamin D, produced as a result of sunlight opening a ring on 7-dehydrocholesterol in the skin
RDA for Vitamin D
600 IU/day
DV for Vitamin D
10 ug/day
What is the most biologically active form of vitamin D?
calcitrol
What are the key functions of calcitrol (vitamin D)?
- maintains body’s concentration of calcium and phosphorus
- regulates immune function
- secretes hormones (insulin, renin, PHT)
Rickets
Disease characterized by inadequate mineralization of the bones caused by poor calcium deposition during growth. This deficiency disease arises in infants and children with poor vitamin D status
Osteomalacia
Weakening of bones that occurs in adults as a result of poor bone mineralization linked to inadequate vitamin D status
UL for Vitamin D
4000 IU
The Vitamin E family consists of…
4 tocopherols and 4 tocotrienols
What is the most biologically active form of vitamin E?
alpha-tocopherol
Vitamin E is commonly found in what foods?
plant oils wheat germ avocado almonds peanuts sunflower seeds
RDA for Vitamin E
15 mg/day of alpha-tocopherol
Hemolysis
Breakdown of red blood cell membranes
90% of Vitamin E is localized where?
adipose tissue
Vitamin E is mostly excreted in ______ but can be excreted through _______ and _______
feces ; urine and skin
Free Radical
Compound with an unpaired electron, which causes it to seek an electron from another compound. Often a strong oxidizing agent.
Peroxyl Radical
Peroide compound containing a free radical, designated R-O-O*, where R is a carbon-hydrogen chain broken off fatty acid and * is an unpaired electron
Functions of Vitamin E?
- regulate free radical activity
- stops lipid peroxidation
Hemolytic Anemia
Disorder that causes red blood cells to break down faster than they can be replaced
UL for Vitamin E
1000 mg of alpha-tocopherol
Vitamin K comes from the ________ family
quinone
Phyloquinone comes from __________ while Menaquinone comes from __________
plants ; fish oil and meats
What is the main dietary form of Vitamin K and also is the most biologically active?
Phylloquinone
Vitamin K is commonly found in what foods?
green leafy vegetables broccoli peas green beans vegetable oil
AI for Vitamin K
90 ug/day for women, 120 ug/day for men
DV for Vitamin K
80 ug/day
Key functions of Vitamin K?
- synthesis of blood clotting factors by the liver
- conversion of preprothrombin to prothrombin
- bone metabolism
Vitamin K has limited storage in the ______ and _____
liver ; bone
Bilirubin
Bile pigment; excess in the blood causes jaundice
