Fat Soluble Vitamins Flashcards
What were the last group of dietary essentials to be recognized
Vitamins
Who stated “Diseases like rickets and scurvy are very likely caused by a lack in the diet of very tiny, even trace amounts of substances which he referred to as “accessory food factors.”
Frederick Hopkins
Who is the Father of Vitamin Research who introduced the term “vitamine”
Casimir Funk
Organic substances required in tiny amounts to promote one or more specific and essential biochemical reactions within the cell that regulates normal body metabolism
vitamins
6 Properties of Vitamins
- organic components of natural foods
- present in food in minute amounts
- essential for development of normal tissue
- when absent from the diet or not properly absorbed or utilized
- cannot be synthesized by the animal
There is no _____ in plants but there are _____ ____, referred to as ____ which are found in ____, ____, ____.
Vitamin A
Vitamin A precursors
fresh green plants, fruits, vegetables
4 Functions of Vitamin A
- required for normal bone growth
- maintains health of epithelial tissues that line or cover body surfaces or cavities (respiratory, urogenital, gastrointestinal lining)
- required for normal night vision
- antioxidant and anti-carcinogenic properties (prevents “free radicals” formation)
3 Deficiency symptoms of Vitamin A
- night blindness
- xeropthalmia
- poor growth
- reproductive failures (abortions, reduced egg production and hatchability)
Sources of carotenoids and Vitamin A
B Carotene:
- green leafy vegetables and yellow vegetables
- fresh pasture, green chop
Factors that decrease carotene content (also degrade vitamin A)
- UV light (sunlight)
- ensiling
- heat
- oxygen
- mold
____ milk is high in vitamin A
colostrum
pure vitamin A
retinol
retinol
chemically unstable so it is best to supplement a synthetic form bound to a volatile fatty acid such as acetic acid
long term ingestion of large amounts may result in toxic symptoms
- anorexia
- weight loss
- skin thickening
- scaly dermatitis
- swelling and crusting of eyelids
- hemorrhaging
- decreased bone strength and eventually death
Vitamin D was discovered to be high in ____ ____ ___
cod liver oil
several sterols have biological vitamin D activity but only two are of major importance
ergosterol and 7-dehydrocholesterol
ergosterol
the chief plant source as growing plants do not contain vitamin D
vitamin D is referred to as the….
sunshine vitamin
exposure of harvested green forage to sunlight for several hours converts ergosterol to…
vitamin D2
7-dehydrocholesterol
found in animal tissues (in the skin)
exposure of animals to sunlight for a few minutes a day converts 7-dehydrocholesterol to…
D3
Conversion of vitamins D2 and D3 to physiologically active form
in the liver – converted to 25 hydroxy D3, in the kidney it is converted to I, 25 dihydroxy D3 (physiologically active form)
functions of vitamin D in its active form (I, 25 D3)
- enhances Ca absorption from the small intestine, essential for normal bone growth and development
- enhances mineralization of bones
symptoms of vitamin D deficiency
- rickets (children), osteoporosis or osteomalacia (adults)
- soft egg shells and reduced egg production
sources of vitamin D
feed sources:
- sun-cured hay
- irradiated yeast
- fish liver oils
vitamin D toxicity
- decalcification of skeletal tissue
- calcification of soft tissue
- decreased appetite along with nausea and headaches
the most commercially available vitamin E is…
tocopherol acetate which is more chemically stable
3 functions of vitamin E
- as an antioxidant, vitamin E ties up excess O2 in oil containing feeds and in the animal body (this action prevents oxidative breakdown of cell membrane fatty acids, thereby maintaining the integrity of cellular membranes
- muscle structure
- reproduction (may enhance fertility)
deficiency symptoms of vitamin E
- muscle dystrophy
- reproductive failures
sources of vitamin E
- whole grains
- vegetable oils
- green forages
Vitamin K is really a group of compounds. The most important natural sources are….
phylloquinone (K1) - common in green vegetables
menaquinone (K2) - a product of bacterial flora in the gastrointestinal tract
menadione (K3) - a synthetic source that is used widely commercially
functions of vitamin k
- required for normal blood clotting
- necessary to synthesize prothrombin in the liver
vitamin k is not a component of prothrombin but acts on….
enzyme systems involved in prothrombin synthesis.
vitamin K is referred to as…
anti-hemorrhage vitamin
deficiency symptoms of vitamin K
prolonged blood clotting time and uncontrolled hemorrhaging
sources of vitamin K
green forages (alfalfa)
fish meal
synthetic form K3
Dicoumarol is found in weather damaged sweet clover hay. If the hay is put in the barn too wet…
- Coumarin, non-toxic mold grows on hay
- dicoumarol, vitamin K antagonist inhibiting blood clotting causes massive internal hemorrhages and death in calves
Warfarin
a competitive inhibitor of vitamin K2 which increases clotting time and eventually becomes toxic (rat poison)
