Nutrition- exam 2- Fat Soluble Vitamins

Question 0

What does your body make when it needs vitamin A?

Answer 0

Retinol binding protein. It carries retinol from the liver (where vitamin A is stored) to body cells

Question 1

Vitamin A - structure

Answer 1

3 forms :
Retinol (alcohol form)
Retinal (aldehyde form)
Retinoic acid (acid form)

Question 2

Where is most of vitamin A stored?

Answer 2

The liver

Question 3

What form of vitamin A affects a person’s vision?

Answer 3

Retinal (aldehyde form)

Question 4

Vitamin A : vision chemistry

Answer 4

Rhodopsin is a visual molecule found in the retina. It is composed of retinal and opsin(a protein).

Light breaks away retinal.

Enzymatic reaction.

Slow process

Question 5

Night blindness

Answer 5

Slow recovery of vision in the dark after bright flash due to vitamin A deficiency.

Question 6

Vitamin A deficiency

Answer 6

Uncommon in US

Takes 1-2 years for symptoms to show because 90% of body’s amount is stored in the liver.

S/S
⋅ xerophtalmia- blindness caused by damage to cornea (progressive /gradual)
⋅keratinization - secretion of keratin (rough, dry, scaly skin)
⋅decrease in mucus secretion

Question 7

What other roles does vitamin A have?

Answer 7

Development of epithelial and goblet cells

BONE REMODELING- vitamin A helps in dismantling bones so they can grow bigger.

Production of steroids and thyroid hormones

Question 8

Beta carotene

Answer 8

Found in carrots

A precursor of vitamin A

Inefficient for providing vitamin A so body usually uses it as an antioxidant instead of converting it into vitamin A

Question 9

Accutane/Retin-A

Answer 9

Accutane - orally. Made from vitamin A but chemically different. Effective but highly toxic (severe birth defects)

Retin-A - topical. Fights acne, wrinkles, other skin disorders. Thins out skin.

**More prone to skin cancer. **

Question 10

Vitamin A toxicity

Answer 10

Free vitamin A damages cells (sorta like free radicals)

S/S
⋅ slow clotting time, birth defects
⋅bone defects- too much vitamin A means too much bone dismantling activity, interferes with vitamin D to maintain normal blood calcium

Vitamin A supplements are a BAD idea

Question 11

Why is vitamin D non essential?

Answer 11

Can be made in the skin with cholesterol and sunlight

Question 12

Vitamin A sources

Answer 12

Liver(with caution)
Dark green vegetables
Deep orange vegetables and fruits (squash, cantaloupe, carrots, sweet potatoes)

Question 13

How does vitamin D increase Calcium absorption?

Answer 13

Calbindin synthesis

Calbindin is a protein needed to absorb calcium. Synthesis of Calbindin requires vitamin D

Question 14

Roles of vitamin D

Answer 14

Elongates intestinal Vili
Increases Calcium absorption
Promotes bone mineralization
Increases TB resistance

Question 15

Vitamin D deficiency

Answer 15

Rickets- bones fail to calcify normally, affects children (bow legged)

Osteomalacia - poor mineralization of bones, affects adults (soft, flexible, brittle and deformed bones)

Osteoporosis - Loss of calcium from bones (results in fractures), elderly

Question 16

What are 3 conditions that are prone to seeing vitamin D deficiency?

Answer 16

Dark skin, breastfeeding, lack of sunlight

Question 17

Vitamin D toxicity

Answer 17

Raises blood calcium concentrations

Forms stones in soft tissues and kidneys

May harden blood vessels

Question 18

Free radicals

Answer 18

Molecules with unpaired Electron

Very reactive - tries to find things to bond with but destroys cells in the process. Antioxidants make compounds with free radicals to prevent damage to cells.

Question 19

Sources of vitamin D

Answer 19

Dairy products (fortified milk)
Sunlight

Question 20

Vitamin D structure

Answer 20

Vitamin D2 - ergo calcification, plant version

Vitamin D3 - cholecalciferol, animal version

Question 21

Vitamin E structure

Answer 21

Tocopherol : 4 forms

Alpha, beta, gamma, delta

Question 22

Vitamin E roles

Answer 22

Fat-soluble antioxidant

Free radicals and fats do not get along!!!

You will find tocopherol in mayonnaise to keep the fat from oxidizing. It helps shelf life.

Question 23

(Vitamin E : Fat-soluble) = (_______: water-soluble)

Answer 23

Vitamin C

Both act as antioxidants

Question 24

Antioxidants are most likely heat sensitive.

Answer 24

True.

Question 26

Vitamin E deficiency

Answer 26

CYSTS IN BREASTS

Question 27

Vitamin E toxicity

Answer 27

Relatively rare b/c Concentrations are regulated by liver

Extremely high doses may interfere with vitamin K activity (blood clotting)

S/S
⋅nausea, cramps, blurry vision, fatigue

Question 28

Vitamin K roles

Answer 28

Activation of clotting factor prothrombin

Bone protein metabolism

Question 28

What two vitamins will interfere with which vitamins?

Answer 28

Extremely high vitamin A (Fat- soluble) will interfere with vitamin C (water-soluble).

Extremely high vitamin E(fat-soluble) will interfere with vitamin K(fat soluble).

Question 29

Sources of vitamin E

Answer 29

Oils
Seeds
Leafy green vegetables

Question 30

Vitamin K deficiency

Answer 30

Primary deficiencies are rare

Secondary deficiency:

ex. decrease in fat absorption, especially true I’m gallbladder removal (gallbladder helps in fat digestion)

Drugs(antibiotics and anticoagulants)
-especially wide spectrum antibiotics b/c they clean out normal microflora. Microflora can synthesize vitamin K.

S/S
Bleeding, weakness

Question 31

Primary deficiencies

Answer 31

Due to not enough intake

Question 32

Secondary deficiency

Answer 32

Body can’t absorb for some reason

Question 33

Vitamin K toxicity

Answer 33

Not common

Jaundice, hemolysis of RBC, brain damage

Reduce effectiveness of anticoagulants

Question 34

Hemorrhagic Disease of the Newborn

Answer 34

Excessive bleeding b/c of less prothrombin (clotting factor) due to a sterile intestinal tract.

Single dose of vitamin K given at birth: orally or by injection

Question 35

Sources of vitamin K

Answer 35

Storage in liver

GI bacteria