Vitamin A Flashcards
Vitamin A is usually structured as:
Retinol
Retinal
Retinoic Acid
Retinyl Esters
Vitamin A also contains forms of ______ that eventually convert into Vitamin A.
Carotenoids
Retinyl Esters contain sources of Vitamin A such as?
Liver
Fish
Liver Oil
Egg Yolk
Butter
Fortified Milk
Carotenoids can be described as (color/texture)?
Deep Orange/Yellow Fruits & Veggies
Dark Leafy Greens / Broccoli
Vitamin A is absorbed as _____ ?
Micelles
Carotenoids convert to vitamin A in the _____ ?
Enterocyte
Vitamin A enters circulation in _____ ?
Chylomicrons
How is Vitamin A transported through the body?
Retinol Binding Proteins
What is essential for Vitamin A absorption?
Protein
Excess vitamin A does what to vitamin K absorption?
Decreases
(A & K compete with each other for absorption)
High B-Carotene intake decreases ______ ?
Vitamin E Levels, Zinc, and Protein
(all needed for retinol binding proteins)
Vitamin A deficiency is also associated with decreased _____ incorporation into RBC’s?
Iron
Vitamin A is used to produce what in the eyes?
Rhodopsin > detection of light
Through cell differentiation, vitamin A can have effects on what?
Gene Expression
Vitamin A is also key for which other human systems?
Immune Function
Bone Growth
Reproductive System
Specific to the immune system, vitamin A functions as a _____ ?
Antioxidant
Carotenoids are involved in decreasing _____ ?
Oxidative Stress
A common vitamin A deficiency is?
Night Blindness
A build of of Carotine in the eyes is known as?
Bilot’s Spots (Reversible with Vit A Supplementation)
Excess Vitamin A is considered?
Quite Toxic
What is the mechanism that allows for Vitamin A to be toxic when consumed in excess?
B/C it is fat soluble, we can store it in excess quantities very easily
What are some symptoms of vitamin A toxicity?
Anorexia
Skin Discomfort
Alopecia
Headache
Synthetic Vitamin A has been used to treat _____, but has also been implicated in causing _____ ?
Acne
Birth Defects
Excess B-Carotene will cause the skin to turn what color & is known as what?
Yellow > Hypercarotenosis
What is the primary method of measurement for vitamin A?
Plasma Retinol Levels
