Vitamins Flashcards
Where did the word vitamin come from?
Vital- amine
What is a provitamin or precursor?
chemically related to vitamin but has no activity until converted into active form.
What is a vitamin antagonist?
chemically related but not active form. Body does not discriminated between the two.
Name this type of vitamin: Made of CHO Ocurrs as provitamins in plants absorbed in the lymph excreted in feces very little synthesis stored in fat
Fat Soluable Vitamins
Name this type of vitamin: CHONPS No form in plants Absorbed in the blood Excreted in the urine Synthesised in the rumen and small intestine limited storage ability
Water soluble vitamin
What is the function of Vitamin A rhodopsin?
Rhodopsin-structural component of light receptor in retina
What is the function of Vitamin A Retinoic acid?
Maintenance of normal epithelial tissue by stimulation of glycoprotein synthesis
Hormone required for collagen synthesis in bone organic matrix, required for mineralization
What are symptoms of a Vitamin A deficiency?
Night blindness- nyctalopia
Keratinization of cornea- xeropthalmia
Thickening and keratiinization of epidermis-hyperkeratosis
increased risk of reparatory infections and genitourinary infections
Impaired bone remodeling, decreased growth
Ataxia a/w spinal nerve damage
Blindness a/w optic nerve damage
Short-tounge syndrome in frogs
What are the results of a vitamin A toxicity?
B/c excess intake of retinoids instead of carotenoids
Bone hypertrophy- decreased bone strength and increase in fractures, joint dysfunction
hyperkeratosis, birth defects
What is preformed vitamin A?
retinoids: retinal, retinol, retinoic acid
Natural and synthetic forms
animal based
What is Pro Vitamin A?
carotenoids ( >500, only 50 with activity)
plant based
What is Vitamin D2?
ergocalciferol
plant source
ergosterol + UV light > ergocalciferol
What is vitamin D3?
cholecalciferol
from animal source
7-dehydrocholesterol + UV light > cholecalciferol
10x more effective than D2 with chickens
After precursors are covered to Vitamin D3 where does it go in the body?
liver > 25- hydroxyvitamin D3
kidney > 1,25-dihydroxyvitamin D3 (active form)
Where is Vitamin E stored?
liver
