Vitamines (Lecture 19)

Question 1

what is a vitamin? (3)

Answer 1

organic compound present in food

not synthesized buy the body

essential for normal growth and function

Question 2

vitamin deficiencies can occur because of … (3)

Answer 2

poverty (malnutrition)

food fads

alcoholics (unbalanced diets because most calories are derived from alcohol)

Question 3

RDA

Answer 3

recommended daily allowance

Question 4

Deficiency in Vitamin B1

Answer 4

Beriberi: extreme weakness, encephalopathy (alcoholics are at greater risk)

Question 5

Deficiency in Vitamin K

Answer 5

Hemorrhage

Question 6

Deficiency in Vitamin B12/ folic acid

Answer 6

megaloblastic anemia

Question 7

Deficiency in Vitamin A

Answer 7

night blindness

Question 8

Deficiency in Vitamin D

Answer 8

osteomalacia and Rickets

Question 9

Deficiency in Vitamin C

Answer 9

scurvy: people become weak, anemic, bruising, bleeding gums, and loose teeth

Question 10

greater risk of vitamin deficiency include: (8)

Answer 10

pregnant women

infants

elderly

chronic diseases (malabsorption)

chronic medications

alcoholics

strict vegans

undernourished populations

Question 11

what are the two major categories of vitamins? and which vitamins are included in these groups?

Answer 11

Water soluble: vitamin B and C

Fat soluble: vitamin A, D, E, K

Question 12

what are fat soluble vitamins?

Answer 12

vitamins that can be stored in body fat for variable amounts of time

Question 13

what are water soluble vitamins?

Answer 13

vitamins that need continuous intake

Question 14

vitamin precursor

Answer 14

beta carotene

Question 15

what are benefits of vitamin A

Answer 15

maintains health of retina tissue

acids in health oil. skin n d mucous membranes

profits normal development of teeth and tissue

Question 16

how is vitamin A involved in vision?

Answer 16

light alters the cis alien bond to one of a trans conformation

the light stimulus will activate rods and cones (rods dim light)

light will disrupt the link between the retinal and opsin to one that is a trans isomer

this loses the in inhibition from the rods to the bipolar cells, which is needed to stimulate the ganglion cells to see

Question 17

deficiency in vitamin A can result in:

Answer 17

abnormal function of epithelial cells (hyperkeratinization, inadequate secretion from mucosal surfaces, which may affect fertility)

impaired immune reponse

Question 18

solution to vitamin A deficiency in underdeveloped countries

Answer 18

genetically modified rice contain gin beta keratin (golden rice)

Question 19

excess vitamin A can cause:

Answer 19

fetal abnormalities

Question 20

when is vitamin D is made by the body?

Answer 20

when exposed to the sun and various foods

Question 21

what is the function of. vitamin D?

Answer 21

promote the proper absorption of calcium

Question 22

steps that occur in the body once exposed to UV

Answer 22

1. skin exposed to uv light
2. uv light interacts with an enzyme, 7-dehydrocholesterol
3. reaction generates pre-vitamin D
4. pre-vitamin D rearranged to form vitamin D

Question 23

where is cholecalciferol (vitamin D3) converted into 25-hydroxyvitamin D3 and by what?

Answer 23

liver, P450s

Question 24

where is 25-hydroxyvitamin D3 converted into 1, 25 hydroxyvitamin D3, and by which enzyme?

Answer 24

kidney, P450

Question 25

what does 1, 25 hydroxyvitamin D3 do?

Answer 25

maintains calcium balance in the body

Question 26

is vitamin D an active hormone?

Answer 26

no, vitamin D is a prohormone, but its metabolites are active

Question 27

how does the active vitamin D act as a hormone?

Answer 27

vitamin D binds to the vitamin D receptor, the receptor heterodimerizes, is taken up by the nucleus, binds to the vitamin D response elements in order to promote th transcription of many genes.

Question 28

which genes are unregulated by vitamin D hormonal activity?

Answer 28

upregulation of proteins supporting bone formation - intestinal Calcium binding proteins (calbindins) - bone matrix proteins, osteoblasts regulation fo type 1 collagen

Question 29

which genes are downregulated by vitamin D hormonal activity?

Answer 29

parathyroid hormone, which decreases calcium absorption from bone

Question 30

Rickets

Answer 30

vitamin D deficiency/ inability to utilize vitamin D weak/soft bones due to extreme calcium loss growth is impaired

Question 31

adults with vitamin D deficiency can acquire...

Answer 31

osteoporosis

Question 32

imbalances between osteoblast and osteoclasts can...

Answer 32

impair bone turnover, thus the maintenance of bone

Question 33

what are the non-classical actions of vitamin D?

Answer 33

antibacterial anti-inflammatory

Question 34

people at risk for vitamin D deficiency include: (9)

Answer 34

breastfed infants older adults sedentary lifestyle obesity restricted sun exposure/pollution dark skin fat malabsorption alcoholism chronic medications (anticonvulsants and antihistamines)

Question 35

vitamin E serves an an...

Answer 35

antioxidant and free radical scavenger. it will protect cell membranes and tissues from free radicals

Question 36

benefits of Vitamin B:

Answer 36

protect cell membranes and tissues from oxidation damage aids in the formation of RBC and use of vitamin K promotes function of healthy circulation system

Question 37

consequences of Vitamin E deficiency: (2)

Answer 37

neurological damage and hemolytic anemia

Question 38

overdosing of Vitamin E may promote:

Answer 38

growth of prostate cancer

Question 39

vitamin E derivative in vapes induced:

Answer 39

lung disease

Question 40

vitamin K function

Answer 40

synthesis of thrombin (coagulation)

Question 41

humans get vitamin K from:

Answer 41

made by intestinal bacteria and dietary intake

Question 42

deficiency of vitamin

Answer 42

cause bleeding

Question 43

warfarin

Answer 43

drug used to decrease blood clot formation by inhibiting vitamin K synthesis

Question 44

function of vitamin C

Answer 44

prom ones healthy immune system helps wounds heal maintains connective tissue aids in absorption of iron

Question 45

ascorbic acid

Answer 45

vitamin C

Question 46

why do we need vitamin C?

Answer 46

most mammals make vitamin c , but humans have a mutation in the gene encoding the enzyme for the final step in vitamin C synthesis from its precursor

Question 47

how is vitamin C involved in enzymatic reactions?

Answer 47

acts as an electron donor in enzymatic reactions

Question 48

vitamin C is important for. the synthesis of

Answer 48

collagen

Question 49

what does vitamin C do to free radicals?

Answer 49

since vitamin C is an antioxidant, it neutralizes free radicals via donating an electron

Question 50

what occurs to excess vitamin C?

Answer 50

vitamin C is not protein bound, thus it is secreted by the kidneys in the urine

Question 51

vitamine B1 (thiamine) function

Answer 51

convert food into. energy aids the function of the heart, cardiovascular system, brain and nervous system

Question 52

functions of vitamin B12 (riboflavin)

Answer 52

promote healthy growth tissue repair release energy form carbohydrates

Question 53

functions of vitamin B3 (niacin)

Answer 53

energy metabolism

Question 54

inability to absorb niacin may cause

Answer 54

``` pellagra (scaly sores) 3Ds: dermatitis diarrhea dementia (death) ``` mucosal changes mental symptoms ``` 3Ds: dermatitis diarrhea dementia (death) ```

Question 55

vitamin B6 (pyridoxine) functions:

Answer 55

maintain healthy brain function formation of RBC breakdown of protein synthesis of antibodies to support immune system

Question 56

Vitamin B9 (follate)

Answer 56

synthesis of DNA and methylation of DNA

Question 57

deficiency in vitamin B9

Answer 57

megaloblastic anemia, bone marrow tries to make RBCs but it releases the RBC before they are fully mature (larger RBC)

Question 58

which vitamins are fortified in foods?

Answer 58

vitamin D (milk) niacin and folate (flour) iodine (salt)

Question 59

how is vitamin B12 absorbed?

Answer 59

vitamin is bound to a protein HCl form stomach frees the vitamin from the protein the vitamin binds to intrinsic factor that is secreted by the parietal cells the intrinsic. factor allows the vitamin to be absorbed in the ileum by the epithelial cells the vitamin separates form the intrinsic factor and then enters the circulation

Question 60

vitamin B12 functions:

Answer 60

role in DNA synthesis myelin synthesis

Question 61

deficiency in vitamin B12 causes:

Answer 61

anemia neuropathy psychiatric abnormalities