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Flashcards in Vitamin Deficeincies Deck (48):
1

B1

Thiamine

2

B2

Riboflaving (FAD, FMN)

3

B3

Niacin (NAD+)

4

B4

Pantothenic acid (CoA)

5

B6

Pyridoxine (PLP)

6

B7

Biotin

7

B9

Folate

8

B12

Cobalamine

9

Which B vitamins are retained the longest?

B12 and folate are stored the longest. Folate>B12

10

Function of Vit A

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

11

Deficiency of Vit A

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

12

Excess Vit A

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

13

B1 function

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

14

Testing for B1 deficeincy

test for transketolase activity, but if suspected treat empirically

15

Wernicke Korsakoff Triad, extra findings

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

16

Korsakoff Syndrome

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

17

Differentiate Dry and Wet Beri Beri

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

18

When do you see thiamine deficiency

alcoholism, secondary to malnutirtion and malabsorption

19

How should thiamine deficiency be treated

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

20

Deficiency of B2

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

21

Sources of B3

dietary intake or synthesis from tryptophan (synthesis requires B6)

22

Deficiency of B3

Niacin deficiency = pellagra = dementia, dermatitis, diarrhea

23

Causes of B3 deficeincy

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

24

Function of B6

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

25

Deficiency of B6

Pyridoxine deficeincy = peripheral neuropathy, sideroblastic anemias

26

B7 function

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

27

What causes B7 deficeincy

egg white heavy diet - avidly binds biotin.

28

Function of B9

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

29

Sources of B9

Folate from leafy green vegetables

30

Deficiency of B9

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

31

Causes of B9 deficiency

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

32

Function of B12

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

33

Function Vitamin C

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

34

Vitamin C deficeincy

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

35

Vitamin C excess

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

36

Sources of vitamin D

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

37

Vitamin D sun synthesis

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

38

Ergocalciferol, cholecalciferol, calcidiol, calcitriol

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

39

causes of vit D deficiency

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

40

Vit D deficeincy

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

41

Vit E function

antioxidant that protects erythrocytes and fatty acids in membranes from ROS

42

Vit E deficeincy

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

43

Excess vitamin E

Hemorrhagic stroke in adults, necrotizing enterocolitis in children

44

Vitamin K function

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

45

Vitamin K deficiency

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

46

Causes of Vit K deficeincy

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

47

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

B1, B2, B3, B5, Lipoic Acid

48

TCA cycle requires what cofactors?

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