Vitamin Deficeincies

Question 1

B1

Answer 1

Thiamine

Question 2

B2

Answer 2

Riboflaving (FAD, FMN)

Question 3

B3

Answer 3

Niacin (NAD+)

Question 4

B4

Answer 4

Pantothenic acid (CoA)

Question 5

B6

Answer 5

Pyridoxine (PLP)

Question 6

B7

Answer 6

Biotin

Question 7

B9

Answer 7

Folate

Question 8

B12

Answer 8

Cobalamine

Question 9

Which B vitamins are retained the longest?

Answer 9

B12 and folate are stored the longest. Folate>B12

Question 10

Function of Vit A

Answer 10

normal differenatiation of specialized epithelium (pancreatic cells, mucus cells); Visual pigments

Question 11

Deficiency of Vit A

Answer 11

Night blindness, Dry skin, Xeropthalmia, vulnerability to infxn (esp. measles)

Question 12

Excess Vit A

Answer 12

Skin changes, Teratogenic, Intracranial HTN (indicated by papilledema); Hepatosplenomegaly

Question 13

B1 function

Answer 13

Cofactor for decarboxylation rxns: Pyruvate dehydrogenase, Alpha-ketoglutarate dehydrogenase, Transketolase, BCAKDH

Question 14

Testing for B1 deficeincy

Answer 14

test for transketolase activity, but if suspected treat empirically

Question 15

Wernicke Korsakoff Triad, extra findings

Answer 15

Classic Triad = (Confusion, Opthalmoplegia, Ataxia) also confabulation, personality change, memory loss (permanent)

Question 16

Korsakoff Syndrome

Answer 16

Prolonged thaimine deficiency leads to permanent damage to mamillary bodies and permanent memory loss

Question 17

Differentiate Dry and Wet Beri Beri

Answer 17

Dry occurs earlier in thiamine deficiency B1. Symmetric polyneuritis, symmetrical muscle wasting. Can progress to WET Beri Beri (High output cardiac failure (dilated cardiomyopathy), edema

Question 18

When do you see thiamine deficiency

Answer 18

alcoholism, secondary to malnutirtion and malabsorption

Question 19

How should thiamine deficiency be treated

Answer 19

Infusion with thiamine. GLUCOSE IS CONTRAINDICATED, can precipitate wernicke encephalopathy

Question 20

Deficiency of B2

Answer 20

Riboflvain deficiency =2 C’s = Corneal vascularization, Cheilosis (inflammed lips and scaling of mouth corners, also stomatitis, glossitis),

Question 21

Sources of B3

Answer 21

dietary intake or synthesis from tryptophan (synthesis requires B6)

Question 22

Deficiency of B3

Answer 22

Niacin deficiency = pellagra = dementia, dermatitis, diarrhea

Question 23

Causes of B3 deficeincy

Answer 23

Hartnup disease (decreased tryptophan absorption), Isoniazid (decreased B6), Malignant Carcinoid Syndrome (increased tyrptophan metabolism)

Question 24

Function of B6

Answer 24

Transamination, decarboxylation - Synthesis of cystathione, heme, niacin, histamine, neurotransmitters (5HT, E, NE, GABA)

Question 25

Deficiency of B6

Answer 25

Pyridoxine deficeincy = peripheral neuropathy, sideroblastic anemias

Question 26

B7 function

Answer 26

cofactor for: Pyruvate carboxylase, Acetyl-CoA carboxylase (malonyl CoA synthesis), ProprionylcoA carboxylase (methylmalonylCoA synthesis)

Question 27

What causes B7 deficeincy

Answer 27

egg white heavy diet - avidly binds biotin.

Question 28

Function of B9

Answer 28

Folate = Converted to THF for nitrogenous base synthesis. Regeneration ofhomocystein via SAM

Question 29

Sources of B9

Answer 29

Folate from leafy green vegetables

Question 30

Deficiency of B9

Answer 30

macrocytic, megaloblastic anemias. Neural tube defects. NO neurologic symptoms. Most commonly seen deficiency. Alcoholics and pregnants.

Question 31

Causes of B9 deficiency

Answer 31

folate deficiency caused by dietary insufficiency, drugs (phenytoin sulfonamides, MTX)

Question 32

Function of B12

Answer 32

cobalamin used for Homocysteind to methionine, Methylmalonyl-CoA to Succinyl CoA, regeneration of homocystein via SAM

Question 33

Function Vitamin C

Answer 33

Fe absorption, Pro/Lys hydroxylation in collagen, DA to NE convertion

Question 34

Vitamin C deficeincy

Answer 34

scurvy = swollen gums, fragile vessels (bruising, hemarthrosis, perifollicular hemorrhage) coiled hair, poor wound healing, subperiosteal hematoma

Question 35

Vitamin C excess

Answer 35

false negative on stool guaic test. Diarrhea. Increased risk of Fe toxicity

Question 36

Sources of vitamin D

Answer 36

D2 = ergocalciferol = plants; D3 = cholecalciferol = consumed in milk, synthesized from skin

Question 37

Vitamin D sun synthesis

Answer 37

7-oh cholecalciferol = in skin; hydroxylated to 25-OH in liver; activated in kidney to 1,25 (OH)2

Question 38

Ergocalciferol, cholecalciferol, calcidiol, calcitriol

Answer 38

ergocalciferol = plant vit D; cholecalciferol = 7-hydroxy = D7; Calcidiol = 25 (OH) = liver; Calcitriol (1,25)OH2; Calcitonin = inhibits calcium resoprtion from bone

Question 39

causes of vit D deficiency

Answer 39

breast milk has low vitamin D, supplement in dark skinned patients;

Question 40

Vit D deficeincy

Answer 40

rickets in children (bone pain and deformity), osteomalacia in adults), hypocalcemic tetany

Question 41

Vit E function

Answer 41

antioxidant that protects erythrocytes and fatty acids in membranes from ROS

Question 42

Vit E deficeincy

Answer 42

hemolytic anemia from fragile RBC, posterior column and spiniocerebellar tract demyelination (lots of phospholipids in long axons) = loss of proprioception and vibration sense and ataxia

Question 43

Excess vitamin E

Answer 43

Hemorrhagic stroke in adults, necrotizing enterocolitis in children

Question 44

Vitamin K function

Answer 44

gama carboxylation of Factors 2, 7, 9, 10 and protein C and S

Question 45

Vitamin K deficiency

Answer 45

not in breast milk, must supplement in neonates; hemorrhage (increased PT and PTT)

Question 46

Causes of Vit K deficeincy

Answer 46

neonates; broad spectrum antibiotics (kills colonic bacteria that snthesize it, Warfarin

Question 47

Cofactors required for pyruvate dehydrogenase, alpha-ketoglutarate DH, branched chain a-ketoacid DH

Answer 47

B1, B2, B3, B5, Lipoic Acid

Question 48

TCA cycle requires what cofactors?

Answer 48

3 NADH, 1 FADH2, 2CO2, 1 GTP per acetyl-CoA