Week 1 self study

Question 1

Common sources of Vitamin A

Answer 1

LIver, egg yolk, butter, while milk,

Fruits and dark green/yellow vegetables are a precursor of Vitamin A

Question 2

Forms of Vitamin A

Answer 2

1. Retinol- serves as a glycosyl donor for some glycoproteins
2. Retinal- aldehyde form of retinol
3. Retonic acid- acid from oxidation of retinal– can’t be reduced so can’t conver to retinol or retinal
4. Beta-carotene- cleaved in the intestine to make two retinal. INefficient actiivty and its antioxidant

Question 3

Mechanism of action of Vitamin A

Answer 3

Retinoci acid binds to receptor proteins and that interacts with chromatin to stimulate retinoid specific RNA synthesis which is important for specific physiolofic functions

Question 4

Functions of Vitamin A

Answer 4

Vision- component of rods and cones

Grwoth- essential for bone growth (retonic acid from promotes growth and differentiation of epithlial cells, but not for vision and reproduciton so ppl with just retonic acid form are blind and sterile from birth)

Taste- needed for kerintinzation of taste buds

Reproduction (retinal and retinol)- support spermatogenosis and fetal resorption in females

Maintainence of epithelial cells- normal differentiation of epithelal cells and mucus secretion

Question 5

Signs of vitamin A deficieny

Answer 5

1. Night blindness/difficulty to see in dim light (dietary)
2. Anemia- needed for transferrin (iron transport) synthesis (dietary)

Acne and psoriasis- can be treated by retonic acid or derivatives (don’t use if pregnant)

Question 6

Ppl likely to have Vitamin A toxicity

Answer 6

1. Ppl who eat polar bear livers (artic explorers)
2. Ppl get acne treatment with retinoic acid
3. Ppl who just take Vitamin A -_-

Question 7

Sources of Vitamin E

Answer 7

VEgetable oilds, grains, leafy vegetables

Moderately in liver and eggs

Question 8

Primary functions of Vitamin E

Answer 8

1. Antioxidant- prevention of oxidation of cell components by molecular O2 and free radicals– it allows itself to be oxidized protecting cells from free radical (moelcuels with unpaired electrons) helping avoid CV disease and cancer

ALso function in immune, DNA repair

More polyunsaturated fatty acids= more oxidation likely= increase in need of Vitamin E

Question 9

Clnical indications of Vitamin U

Answer 9

Oxidative damage to DNA by free radicals is thought to be the cause of many cancers. So Vitamin E neutralizing the free radicals is a center of study althoguh no incidence found yet.

Question 10

Facts about water soluble

What are they?

Where can you get them?

Storage?

Food prepration?

Answer 10

Vitamin C- citrus fruits

Vitamin B1,2,3,5,6,7,9,12- grains, meat, poultry, eggs, fish, milk, legumes and fresh vegtable

Water soluble are not stored in the body- when they exceed renal threshold they are excreted and need to be replaced daily

Can be easily destroyed. SO keeping away from light and refrigerating can help perserve the vitamins nutrients.

Question 11

Disease of vitamin C defieicny

Answer 11

Scurvy, hemorrages, decreased leuokocyes and histamine release

Question 12

Vitamin B defieicny

Answer 12

To B1- thiamine- ataxia, beriberi

Reason Riboflavin- B2- oral ocular genital syndrom

NeverB3 Niacin Pellegra

Pays B5 Pantothenic acid rare- mimic other deficiencies

ParticularryB6 Pyridoxine- sideroblastic anemia, neurppathy, depresion

Be Biotin- anemia, fatigue, dermatitis

Fore Folic acid- inhibtion of DNA synthesis, megoblastic anemia

Crime Cobalamine B12 megoblastic anemia