Fat-Soluble Vitamins
What factors affect bioavailability of vitamins?
1. Amount in the food 2. Way the food is prepared 3. How easily the food is digested and absorbed 4. Individuals nutritional status 5. Whether the vitamin is natural or synthetic
Name several functions of vitamin A in the body.
1. Vision 2. Cell Differentiation 3. Immune Function 4. Bone growth 5. Sperm production and fertility 6. Cell maintenance
What is beta carotene?
A provitamin which can be converted into Vitamin A
What is the job of retinol-binding protein?
Absorb light; changes shape of the vitamin A
What is Accutane? What is it used for? What is a potential side effect to monitor?
Accutane is a retinoid containing medicine Used to treat acne problems Side effects: Crohn's disease, liver damage, depression, birth defects or miscarriages
Name some food sources of vitamin A.
Active forms: Dairy, Fish, Meat Carotenoids (can be converted to vitamin A): sweet potatoes, carrots, spinach, red peppers, tomatoes
Where is most vitamin E stored?
Adipose tissue (rest is stored in cell membranes)
What is the primary function of vitamin E?
Antioxidant!
Name a carotenoid.
Beta-carotene; can be used to make vitamin A in the body
What are the chief roles of vitamin K in the body?
Blood coagulation Bone health
Vitamin D is required for absorption of what mineral?
Calcium
How does a vitamin E deficiency affect red blood cells?
Causes premature breakdown of RBCs
The effects of vitamin A deficiency are most severe in what population group?
Children
What is vitamin K transported by?
Chylomicrons
What is a usual and reliable source of vitamin D in the diet?
Dairy and fish
How do antibiotics affect vitamin K production?
Destroys the bacteria in the gut that helps produce a major portion of the vitamin K in the body
Fat-soluble vitamins are solvent in what solution?
Dietary fat
How does vitamin E affect free radicals?
Donates an electron to them to stabilize them, and prevent them from causing damage
What does the term pro-vitamin mean?
Found in foods that are not directly usable by the body but can be converted into an active vitamin once absorbed
Why shouldn't you eat polar bear liver?
It is rich in vitamin A --> toxicity
Where is most of the body's vitamin A stored?
Liver
Where is vitamin K mainly stored?
Liver
What organs in the body are used to synthesize vitamin D?
Liver and Kidneys
Which form of vitamin K comes from animal sources?
Menaquinone Can be synthesized by our gut bacteria
What protein carrier transports fat-soluble vitamins from the small intestines to general circulation?
Micelle and Chylomicrons
Name the only plant source of vitamin D.
Mushrooms
Deficiency of vitamin A in third-world countries results in what condition?
Night blindness Hyperkeratosis
During which time of the year does Kentucky NOT receive UVB rays?
November-March
Name a major source of vitamin E in the diet.
Oils
What is the adult version of the vitamin D deficiency Rickets?
Osteomalacia
Define xerophthalmia.
Permanent damage to the cornea causing blindness due to prolonged vitamin A deficiency
Which form of vitamin K comes from plant sources?
Phylloquinone (P = PLANTS) Most active form in body
Vitamin K is routinely given in a single dose to individuals at what stage of development?
Premature infants just before birth
The dietary carotenoid lycopene protects against what cancer?
Prostate cancer
What factors affect bioavailability of fat-soluble vitamins?
Requirement of bile salts and micelle
What form of vitamin A is used for vision?
Retinal
What is the active form of vitamin A?
Retinol
Describe what happens to children who do not get adequate vitamin D in childhood.
Rickets
What is the greatest source of vitamin D?
Sunlight (UVB radiation)
What are retinoids?
The family or group of substances that include retinol, retinal, and retinoic acid
What are carotenoids?
The yellow-red pigments that give carrots, butternut squash, and cantaloupe their vibrant, deep orange color; Provitamin A carotenoids include beta-carotene that can be used to make vitamin A in the body
Vitamin A supplements may be teratogenic. What does that mean?
They can cause birth defects or fetal development
How many different forms of vitamin A are active in the body?
Three
What is a free radical?
Unstable oxygen-containing molecule that can damage cells and steal energy
Vitamin E activity is enhanced by what vitamin?
Vitamin C
Name the fat-soluble vitamins.
Vitamin D, E, A, K
What is the relationship between vitamin E and vitamin A?
Vitamin E protects vitamin A from oxidation
What is the main function of vitamin K?
Vitamin K is a coagulant! Blood clotting. (K = KLOTTING)
Which fat-soluble vitamins are in milk?
Vitamins A, D, K