Vitamin

Question 1

What are the lipid soluble vitamins? Is toxicity or deficiency more of the problem?

Answer 1

A, D, E, K; toxicity more of a problem since they are more easily stored

Question 2

What are the water soluble vitamins? Is toxicity or deficiency more of the problem?

Answer 2

B, C; deficiency since they are more easily excreted in urine

Question 3

What functions is Vitamin A involved in?

Answer 3

Visual cycle with rhodopsin and cone opsins; synthesizing glycoproteins and mucosaccs; retinoic acid as a hormone; antioxidant

Question 4

What are Vitamin A deficiencies?

Answer 4

Night blindness, xerophthalmia later; follicular hyperkeratosis (like goosebumps); anemia; poor growth in kids; increased vulternability to infection and cancer

Question 5

Who is susceptible to Vit A deficiencies?

Answer 5

Poor, malnourished, premature babies

Question 6

What is the order of retinoic acid formation from beta carotene?

Answer 6

Beta carotene –> all-trans retinol –> all trans retinal –> retinoic acid (hormone) –>gene transcription

Question 7

What are the functions of Vit D?

Answer 7

Maintaining bone and calcium homeostasis; could have wide range of activity, but definitely acts as hormone

Question 8

What are Vit D deficiencies?

Answer 8

Rickets in kids; osteomalacia in adults; increased vulnerability to cancers like breast, metabolic syndromes, infections

Question 9

Who’s susceptible to Vit D?

Answer 9

Poor, elderly, alcholics; other groups with mild deficiencies

Question 10

Although toxicity is rare, what does excess Vit D lead to?

Answer 10

High serum levels of calcium and bone loss

Question 11

What is thought to contribute to correlation between Vit D levels and cancer risk?

Answer 11

The vitamin D receptor

Question 12

What is the function of Vit K? What does it catalyze?

Answer 12

Localizing of the enzymes required for clotting; it catalyzes addition of gamma-carboxyglutamate to clotting enzymes

Question 13

What are Vit K deficiency consequences?

Answer 13

Easy bruising, bleeding, hemorrhage

Question 14

Who is susceptible to Vit K def?

Answer 14

Newborn infants (lacking klebsiella); long-term antibiotics and patients; elderly or those with defects in fat absorption

Question 15

What structure does Vit K have?

Answer 15

Quinone ring

Question 16

How does warfarin act as an anticoagulant?

Answer 16

It inhibits Vit K’s activities

Question 17

What does Vit E do?

Answer 17

Serves as an ANTIOXIDANT to scavenge free rads; protect membranes from damage and prevent oxidation of LDL (foam cells potentially)

Question 18

If you had a Vit E deficiency what would you see?

Answer 18

Cardiovascular disease, neurological symptoms (Vit E can be in the myelin sheath)

Question 19

Who is susceptible to Vit E deficiency?

Answer 19

Patients with severe prolonged defects in absorption (e.g. celiac disease) or genetic defects

Question 20

What is Vit C responsible for?

Answer 20

Cofactor for oxidases involved in collagen formation; needed for steroid synthesis in stress response; aids in iron absorption; antioxidant

Question 21

What do you see with Vit C deficiencies (mild and severe)?

Answer 21

Bruising, immunocompromised; severe is scurvy (decreased wound healing, osteoporosis, hemorrhage, anemia, fatigue, corkscrew hairs, pinpoint hemorrhages);

Question 22

Who is susceptible to Vit C deficiencies?

Answer 22

People with poor diet, smokers

Question 23

What specific reactions is Vit C involved in?

Answer 23

Prolyl and lysyl hydroxylases for collagen biosynthesis; also epi synthesis

Question 24

What are the B-complex vitamins?

Answer 24

Thiamine (B1), Riboflavin (B2), Niacin (B3), Biotin, Pantothenic acid (B5), Pyridoxine (B6); Folate (B9) and Cobalamin (B12)

Question 25

What are common effects of deficiency of energy-releaseing B vits?

Answer 25

Dermatitis, glossitis, diarrhea; nervous system affected, peripheral neuropathy, depression/confusion, lack of coordination, malaise

Question 26

What is the function of B1?

Answer 26

Required cofactor for several enzymes; critical in nervous system

Question 27

Deficiencies of B1?

Answer 27

Mild: GI; depression, fatigue (poor, elderly); Moderate: Wernicke-Korsakoff syndrome (alcoholics); Severe: Beriberi (people dependent on polished rice, perhaps alcoholics)

Question 28

What do you see in Wernicke-Korsakoff?

Answer 28

Mental disturbance, unsteady gait, uncoordinated eye movements; perhaps CHF

Question 29

What is beriberi characterized by? What is the difference between dry and wet?

Answer 29

Extreme muscle weakness, poly-neuropathy, heart failure; in wet beriberi, we see edema

Question 30

What is riboflavin a precursor to?

Answer 30

FAD and FMN

Question 31

What does a B2 deficiency lead to?

Answer 31

Ariboflavinosis: rash around nose, inflammation of mouth and tongue, burning and itchy eyes, light sensitivity (uncommon)

Question 32

Susceptible groups for B2 deficiency?

Answer 32

Alcoholics (deficiency uncommon)

Question 33

What is niacin a precursor to? Who could you give it to?

Answer 33

NAD and NADP; hypercholesterolemia or hypertriglyceridemia patients

Question 34

What can cause biotin deficiency?

Answer 34

Eating a lot of raw eggs

Question 35

What is pantothenic acid (vit B5) required for?

Answer 35

CoA synthesis

Question 36

What is pyridoxine a precursor to? What else is it required for?

Answer 36

PLP; required for glycogen breakdown and GABA and heme synthesis

Question 37

What are deficiencies characterized by (mild and severe)

Answer 37

Mild: irritability, nervousness, depression; Severe: pripheral neuropathy, convulsions, decreased glucose tolerance, hyperhomocysteinemia, anemia

Question 38

Who’s susceptible to deficiency?

Answer 38

Patients treated with certain drugs, like the TB drug isoniazid