chapter 7-2 Flashcards
(28 cards)
early sign of vitamin A deficiency
night blindness
deficiency of vitamin A is the product of
keratin leading to keratinization
keratin is produce by
cornea cells
one of the early stage of keratinization is
Bitot’s spots in its mildest form
keratinization leads to
xerosis ending in zerophtalmia
keratin protein characteristics
dry, firm, possibly cloudy cells
xerophthalmia in final stages
infection
hemorrhage
permanent blindess
vitamin A is required to maintain
the healthy epithelial tissue
vitamin A deficiency affects
gene regulation/gene expression
numerous types of cells and the immune system are affected by vitamin A deficiency, resulting in
the body becomes vulnerable to infection
downward spiral of malnutrition and infectionblindess
Vitamin A participates in
sperm development
Vitamin A supports
normal fetal development
vitamin A works with
osteoclasts to prepare the bone surface for new growth
vitamins D and K work with osteoblasts to add
calcium, phosphorus, magnesium, and fluoride into new bone layer for growth repair and maintenance
excessive vitamin A could
push too much removal of the layers of bone faster than new ones could be formed.
can thin and weaken bones
vitamin A toxicity is
one of the two most toxic vitamins
possible causes of vitamin A toxicity
supplements and fortified foods
fish oil supplements
limit liver to abt 4 ounces every 14-15 days
higher risk groups for vitamin A toxicity include
pregnant women
toddlers and children
adolescents
beta-carotene food sources
dark green and dark yellow veggies and fruits
functions of beta carotene
precursors for vitamin A
an antioxidant protecting macula from oxidative damage
carotenoid are often stored in
the layer of fat just under the skin
vitamin D is one of the two
most toxic vitamins
vitamin D’s precursor
cholesterol within the skin
functions of vitamin D
aids bone and body growth
stimulates maturation of cells
