Chapter 12: Fat-Soluble Vitamins (A,D,E,K) Flashcards
What is a vitamin?
an essential organic component needed for energy metabolism, growth, & development/mantinence
What vitamins are fat-soluble? What vitamins are water-soluble?
fat-soluble = A,D,E,K water-soluble = B,C
How does cooking affect vitamins?
it destroys them
Describe in detail Vitamin A and vision, Vitamin D and Calcium homeostasis
vit A is needed for the retina, if vit A is depleted, night vision is impared. Vit D is needed to maintain bone health & help regulate immune function, secretion of hormones, & the cell cycle
Vitamin A
functions: vision, cell differentiation, growth/development, immune function, can be used to treat acne
sources: animal products (retinoids), the yellow-orange pigment in fruit & veg (carotenoids)
deficiency: rare in North America, night blindness, skin, & impairment in growth
toxicity: upset GI tract, headaches, dizziness, liver damage, hair loss, teratogenic effects are fetal malformation & spontaneous abortion
Vitamin D
functions: maintain bone health, increase absorption of Ca & P
sources: sunlight, fatty fish, fortified dairy & breakfast cereal (ergocalciferol)
deficiency: rickets (childeren) = abnormal bone
mineralization, bowed legs, enlarged head,
joints, & ribcage
osteomalacia (adults) = “soft bones” from
poor calcification, bone fractures
toxicity: doesn’t occur from supplementation or diet
Vitamin E
functions: as an antioxidant, maintains cell membrane integrity, prevents chain reactions, reduced oxidative stress
sources: plant oils, wheat germ, almonds & peanuts, avocado, sunflower seeds (tocopherol)
toxicity: can interfere w/ vit K in blood clotting & cause hemorrhages
deficiency: immune impairments, neurological changes, premature breakdown of RBCs (hemolysis)
Vitamin K
functions: blood clotting, bone metabolism
sources: leafy greens, broccoli, plant oils, margarine
toxicity: no UL, easily excreted
deficiency: rare, poor clot formation, hemorrhaging
