Fat Soluble Vitamins

  1. Name 3 active forms of Vitamin A and describe functions of each.
    • Retinol: Form of vitamin A you get from the diet, supports reproduction (menstrual cycle and sperm development), major transport and storage
    • form of the vitamin.
    • Retinal: Active in vision, intermediate in the conversion of retinol to retinoic acid.
    • Retinoic Acid: Acts like a hormone, regulates cell differentiation, growth (bone elongation), immunity and embryonic development, normal development of
    • epithelial linings, cell development (differentiation).
  2. What are carotenoids?
    Pigments commonly found in plants and animals, some of which have vitamin A activity; the carotenoid with the greatest vitamin A activity is beta-carotene.
  3. What types of cells are affected by vitamin A deficiency?
    proteins and epithelial cells.
  4. Describe the drug Accutane. Why do doctors require female patients to use birth control while taking Accutane?
    Accutane is made from retionoic acid; it’s effective against deep lesions of cystic acne.

    Itis highly toxic, especially during growth, and has caused birth defects in infants when women have taken it during their pregnancies; that’s why doctors recommend women to use two effective forms of contraception at least once a month after discontinuing its use.
  5. Describe the various roles of vitamin D in the body.
  6. Increase/maintain the absorption of calcium
    • Regulation of phosphorus
    • Immunity
    • Prevents cancer tumor growth
    • Muscles-Stronger muscles with increased vitamin D
    • Reproduction
    • Lower blood pressure
    • Cellular metabolism
    • Blood clotting
    • Nerve transmission
    • Muscle contraction
  7. When calcium is adequate in the diet, on which target tissue does active vitamin D act primarily?
  8. What percent of dietary calcium is absorbed when normal amounts of vitamin D are present in the body?
  9. Under what conditions are longer sun exposures needed for production of vitamin D?
    • Dark skin
    • Elderly - Can only make ¼ vitamin D compared to when they were younger.
    • Latitude - No sun exposure in the north.
    • Pollution
    • Sunscreen - Anything over 8 SPF will decrease vitamin D synthesis.
  10. Describe the function of vitamin E in the body.
    • Antioxidant
    • Stabilize cell membranes
    • Regulate oxidation reactions
    • Protect polyunsaturated fatty acids and vitamin A
  11. What are free radicals and how are they formed? What parts / molecules of the cells are vulnerable to damage from free radicals?
    Free radicals: Uncharged molcules (typically highly reactive and short lived), having an unpaired valence electron.Phospholipids of the bilayer membrane are damaged by free radicals.

    Vitamin E is an antioxidant that neutralizes free radicals and prevents the oxidation of polyunsaturated fatty acids and protects other lipids and related compounds.
  12. What form of vitamin E is most biologically active in the body?
  13. Which form of vitamin E in supplements is better utilized in the body, natural or synthetic? What is the isomeric form of natural and synthetic alpha tocopherol in supplements?
    Natural form (D) of vitamin E is better utilized than synthetic (DL).
  14. List the best food sources for vitamin E.
    • Polyunsaturated plant oils (margarine, salad dressings, shortenings)
    • Leafy green vegetables
    • Wheat germ
    • whole grains, nuts, seeds
    • Liver
    • fatty meats
    • egg yolks, dairy
    • Get the majority of Vitamin E from fats and oils
  15. What drug is enhanced by high intakes of vitamin E. What effect does this have in the body?
    • Extremely high doses of vitamin E may interfere with the blood-clotting action of Vitamin K and enhance the effects of drugs used that oppose blood-clotting called anti-coagulants, causing hemorrhage/increase
    • bleeding.
  16. What are the primary functions of vitamin K in the body?
    Synthesis of blood-clotting proteins and bone proteins; bone mineralization
  17. What is osteocalcin and what is its function in bone? How does vitamin K affect osteocalcin?
    • Osteocalcin is a protein found in the bone that is secreted solely by osteoblasts and was thought to play a role in the body’s metabolic regulation and is
    • pro-osteoblastic (bone-building).

    Implicated in bone mineralization and calcium ion homeostasis.Vitamin K and osteocalcin are instrumental to make bones harder.
  18. What are the major foods and non-food sources of vitamin K?
    Food: Liver, leafy green vegetables, cabbage-type vegetables, milk, eggs

    Non-food: Bacterial synthesis in the digestive tract (makes 50% of your needs).
  19. Is vitamin K deficiency common or rare? Under what conditions can vitamin K deficiency occur? What are the symptoms of vitamin K deficiency?
    Vitamin K deficiency is rare.

    • Secondary deficiency may occur in two circumstances:
    • Whenever fat absorption falters, as occurs when bile production fails, vitamin K absorption diminishes.
    • Some drugs disrupt vitamin K synthesis and action in the body - antibiotics kill the vitamin K-producing bacteria in the intestine and anti-coagulant drugs interfere with vitamin K metabolism and activity.

    Symptoms of vitamin K deficiency: Hemorrhaging.
  20. Why do infants receive a dose of vitamin K at birth?
    • Infants are born with a sterile intestinal tract, and vitamin K-producing bacteria take weeks to establish themselves; and plasma prothrombin is
    • low (this reduces the likelihood of fatal blood-clotting during the stress of birth).

    Vitamin K is not transferred from the mother to the child.Infants are susceptible to hemorrhaging.
  21. What effect does high levels of vitamin K have on anticoagulant drugs?
    High doses of vitamin K can reduce the effectiveness of anticoagulant drugs used to prevent blood clotting. Increasing vitamin K will increase blood clotting.
Card Set
Fat Soluble Vitamins
Fat soluble vitamins