Vitamin A Flashcards
What are the Essential organic substances in minute amounts
Vitamins
Three distinctive characteristics of fat soluble vitamins
Organic compounds:
◦Contain C, H, O
◦Only water soluble has N
◦Some have S and Co
What are the substances that interfere with the normal functioning of a vitamin
Antivitamins or vitamin antagonists
What do you call a vitamin that is man-made or synthesized in the laboratory
Synthetic vitamins
What do you call the multiple forms of a vitamin (analogues/isomers)
Vitamers
What are substances that have physiological roles like vitamins but they are present in larger amounts and partially synthesized in the body
Vitamin–like compounds
too much or too little - > unhealthy
Vitamin malnutrition
result of lack of vitamin, later stage -> more defined signs and symptoms
Avitaminosis
vitamin toxicity due to excessive accumulation in the body
Hypervitaminosis
how many vitamins is considered essential for human nutrition
15 vitamins
Generally have precursors/ provitamins Stored in the body Deficiencies are unlikely Not absolutely needed daily Generally stable (ordinary cooking)
FAT-SOLUBLE
Do not have precursors Not stored significantly Deficiency develops fast Must be supplied daily Generally unstable (ordinary cooking)
WATER-SOLUBLE
Old names of Vitamin A
antixerophthalmic vitamin,
anti-infective vitamin,
opthalmin,
axerophtol
What do you call the Preformed Vit A
Retinoids (retinal, retinol, retinoic acid)
What are the provitamin A
◦Carotenoids
◦Must be converted to retinoid form
The acid that is required for structural components of eye and is necessary for cellular differentiation
Retinoic acid
What turns the visual light into nerve signals in retina of eye / oxidized form of vitamin A.
Retinal
foamy, soapsud-like spots on the conjunctiva
Bitot`s spot
dry, hazy and rough appearing cornea
Corneal xerosis
crater-like defect on the cornea
Corneal ulcer
Softened cornea; sometimes bulging
Keratomalacia
Sources of preformed vit A
Liver, fish oils, fortified milk, eggs, other fortified foods
Sources of Provitamin A carotenoids
◦Dark leafy green, yellow-orange vegetables/fruits
Recommended intake of vitamin A for males
Males (>19 yrs): 700