fat soluble vitamin

Question 1

Fat soluble vitamins

Answer 1

ADEK

Question 2

Preformed

Answer 2

*Retinoids (retinal, retinol, retinoic acid)
*Found in animal products

Question 3

*Provitamin A

Answer 3

*Carotenoids
*Must be converted to retinoid form
*Found in plant products

Question 4

carotenoids to retinoids

Answer 4

*Enzymatic conversion of carotenoids occurs in liver or intestinal cells, forming retinal
and retinoic acid

Question 5

Provitamin A carotenoids

Answer 5

*Beta-carotene
*Alpha carotene
*Beta-cryptoxanthin

Question 5

Retinoic acid is required for structural
components of eye

Answer 5

*Cones in the retina: *Responsible for vision under bright lights& *Translate objects to color vision
*Rods in the retina: *Responsible for vision in dim lights & *Translate objects to black and white vision

Question 6

Retinoic acid

Answer 6

cellular differentiation, Embryo development, gene expression

Question 7

Retinoic acid influences

Answer 7

production, structure, and function of epithelial cells that line the outside (skin) and external passages (mucus forming cells) within the body

Question 7

vitamin A deficiency

Answer 7

leads to decreased resistance to infections

Question 8

Sources of Vitamin A

Answer 8

*Dark leafy green, yellow-orange
vegetables/fruits

Question 9

absorption of vitamin a: carotenoids

Answer 9

*Absorbed intact, absorption rate much lower
*Intestinal cells can convert carotenoids to retinoid

Question 9

absorption of vitamin a: retinoids

Answer 9

Retinyl esters broken down to free retinol in small intestine - requires bile, digestive enzymes, integration into micelles

Question 9

transport and storage of vitamin a

Answer 9

*Liver stores 90% of vitamin A in the body
*Reserve is adequate for several months
*Transported via chylomicrons from intestinal
cells to the liver
*Transported from the liver to target tissue as
retinol via retinol-binding protein, which is
bound to transthyretin

Question 9

excretion of vitamin A

Answer 9

*Not readily excreted
*Some lost in urine
*Kidney disease and aging increase risk of
toxicity because excretion is impaired

Question 9

toxicity of vitamin a

Answer 9

*GI effects
*Headaches
*Blurred vision
*Poor muscle coordination

Question 9

Hypervitaminosis A

Answer 9

results from long-term supplement use (2 – 4 x RDA

Question 9

vitamin a deficiencies

Answer 9

*Xerophthalmia
*Night blindness
*Follicular hyperkeratosis

Question 9

Teratogenic (may occur with as little as 3 x RDA
of preformed vitamin A)

Answer 9

*Tends to produce physical defect on
developing fetus
*Spontaneous abortion
*Birth defects

Question 10

classification of vitamin D

Answer 10

Vitamin D3 (Cholecalciferol) & Vitamin D2 (Ergocalciferol)

Question 11

Ergocalciferol (D2)

Answer 11

is synthesized in plant and fungi when ergosterol undergoes photolysis under UV light

Question 12

Cholecalciferol (D3)

Answer 12

is synthesized in skin of animals by photolysis of 7-dehydrocholesterol

Question 13

Bioactivation occurs through 2 steps

Answer 13

• Hydroxylation in liver produces calcidiol
• Hydroxylation in kidney produces calcitriol

Question 14

Functions of vitamin d

Answer 14

i. Maintains structural integrity of bones & bone growth by regulating use of calcium + phosphate (bone turnover) (Calcitriol)

ii. Maintains serum Ca and P homeostasis

iii. Play a role in immune function and protection from chronic diseases

Question 15

Vitamin D sources

Answer 15

Fortified foods (milk and orange juice)
* Fish liver oil = Cod liver oil contains over 1000IU/tablespoon
* Fatty fish (salmon, tuna)
* Liver, beef
* Sunlight exposure = 5-30 minutes in direct sunlight at mid-day
* Supplements

Question 16

avsorption, transprot and storage

Answer 16

Absorptive cells: incorporated into chylomicrons -- Enter lymphatic systems -- Enter plasma by transcalciferin -- Stored in the liver (little)

Question 17

toxicity

Answer 17

only occurs when you take more than 40 000IU of vitamin D per day over a long period of time

Question 18

Effects of Vitamin D Toxicity

Answer 18

* Loss of appetite * weight loss * anorexia * muscle fatigue and weakness * vomiting * cramping * constipation * frequent thirst and urination

Question 19

rickets

Answer 19

*Softening of bones due to insufficient vitamin D *Sufficient collagen, lack calcium *Cause bow and fractures

Question 20

Vit E: Classification

Answer 20

tocopherol, Tocotrienol

Question 21

Absorption of vit e

Answer 21

Absorbed in the upper small intestine by micelle-dependent diffusion

Question 22

Storage of vit e

Answer 22

membranes and adipose tissues

Question 23

excretion

Answer 23

feces and urine

Question 24

functions of vit e

Answer 24

Antioxidant in the cell

Question 25

how vit e is antioxidant in the cell

Answer 25

 Prevent oxidative degradation by ROS  Protects PUFAs  How: As a membrane free radical scavenger (donate H atom)  Involving SOD, GPX and catalase (enzyme)  Reduce oxidative stress

Question 26

Functions of vit e other than antioxidant

Answer 26

Inhibits platelets aggregation (clot) Enhances vasodilation

Question 27

Toxicity of vit e

Answer 27

 Decrease the body’s ability to use other fat-soluble vitamins  Impaired blood clotting

Question 28

deficiencies of vit e

Answer 28

Loss of muscle coordination, vision, immune functions Hemolytic anemia in children Premature infants Male infertility (animal study)

Question 29

Vit K: Classification

Answer 29

Vitamin K1 (Philloquinones) / Vitamin K2 (Menaquinones) / Vitamin K3 (Meadione)

Question 30

Absorption, Transportation and storage of k1

Answer 30

By an energy-dependent process in the small intestine

Question 30

Absorption, Transportation and storage of k2 and k2

Answer 30

By passive diffusion in the small intestine

Question 31

Functions of vit k

Answer 31

Aids in blood clotting

Question 31

absorption

Answer 31

Incorporated into chylomicrons in the lymph , then into liver , into VLDL and into peripheral tissues

Question 32

how vit k Aids in blood clotting

Answer 32

 Initiates the healing process by slowing and stopping the bleeding  Given to patients before surgery to prevent excessive bleeding  Vitamin K is the coenzyme to Vitamin K-dependent coagulation proteins in the blood coagulation cascade known as factors II, VII, IX, and X

Question 33

how vit k Aids in Ca absorption

Answer 33

 Aids in the prevention and treatment of osteoporosis and the loss of bone density  Vitamin K activates a protein called osteo-calcin which is responsible for building and maintaining strong bone tissue  Vitamin K’s role is enhanced when taken with Vitamin D and magnesium which helps maintain healthy bones

Question 34

sources of vit k

Answer 34

Dark green vege, dairy products, meat, eggs, fruits and cereals

Question 35

Deficiencies of vit k

Answer 35

Hemorrhage (bleeding from ruptured blood vessels) Heavy menstrual bleeding Hip fractures