Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

USMLE Step 1 Random Facts > Vitamins > Flashcards

Vitamins Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards
1
Q

B1

A

thiamine: TPP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

B2

A

riboflavin: FAD, FMN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

B3

A

niacin: NAD+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

B5

A

pantothenic acid: CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

B6

A

pyridoxine: PLP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

B7

A

biotin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

B9

A

folate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

B12

A

cobalamin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

C

A

ascorbic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

fat soluble vitamins

A

A,D,E,K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

vit A (retinol)

A
  • antioxidant
  • visual pigments (retinal)
  • normal diff of epith cells into specialized tissues
  • prevents squamous metaplasia
  • tx of measles, AML M3
  • in liver (esp polar bears), leafy vegetables, beta-carotene (carrots)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

vit A (retinol) deficiency

A
  • night blindness
  • dry skin
  • bitot spots (dry spots on conjunctiva)
  • keratomalacia (wrinkling/clouding of cornea)
  • xerophthalmia
  • corneal ulcerations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

vit A (retinol) excess

A
  • arthralgias, fatigue, HA, sore throat
  • alopecia
  • skin changes (oranging of skin, dry/pruritic skin)
  • teratogenic (cleft palate, cardiac abnorm)
  • increased ICP (pseudotumor cerebri)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

vit B1

A
  • TPP = active form
  • cofactor for enzymes in decarboxylation rxns (pyruvate DH, alpha-ketoglutarate DH, transketolase, branched-chain AA DH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

vit B1 deficiency

A
  • ATP depletion (from impaired glucose breakdown) –> WORSENED w/ glucose infusion
  • brain/heart affected first (highly aerobic)
  • Wernicke-Korsakoff synd
  • Dry beriberi (neuritis, symm muscle wasting)
  • Wet beriberi (high-output cardiac failure, dilated cardiomyopathy, edema)
  • seen in alcoholics, in malnutrition, and in pts on dialysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

vit B2

A
  • cofactor in oxidation/reduction
  • FAD (cofactor for succinate DH + component of ETC complex II)
  • FMN (component of ETC complex I)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

vit B2 deficiency

A
  • “mouth and eyes”
  • cheilosis (inflamm of lips, scaling/fissures @ corners of mouth)
  • corneal vascularization
  • dermatitis
  • stomatitis
  • glossitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

vit B3

A
  • NAD+/NADP - used in redox rxns
  • derived from tryptophan
  • synth req B6 + B2
19
Q

vit B3 deficiency

A
  • glossitis
  • **pellagra: (if severe); aka caused by:
  • Hartnup dz - decreased tryptophan absorp
  • malig carcinoid synd (increased tryptophan metab)
  • INH (decreases B6)
20
Q

vit B3 excess

A

facial flushing

21
Q

vit B5

A

-component of CoA + fatty acid synthase

22
Q

vit B5 deficiency

A
  • dermatitis
  • enteritis
  • alopecia
  • adrenal insuff
23
Q

vit B6

A
  • pyridoxal phosphate = active form
  • used in transamination (ALT, AST) and decarboxylation rxns
  • cofactor for glycogen phosphorylase
  • synth of cystathionine, heme, niacin, histamine, NT (serotonin, epinephrine, NE, GABA)
24
Q

vit B6 deficiency

A
  • convulsions (bc decreased GABA)
  • hyperirritability
  • periph neuropathy (deficiency inducible by INH + oral contraceptives)
  • sideroblastic anemias (due to impaired Hb synth and Fe excess) - bc lack of ALA-S enzyme
25
Q

best enzyme to test B1 deficiency?

A

transketolase

26
Q

“tea and toast” diet deficiency?

A

B3 (niacin)

27
Q

vit B2 impt for what enzymes?

A
  • succinate DH (TCA)
  • fatty-acyl CoA DH (beta-oxidation)
  • glycerol phosphate shuttle
28
Q

B7 cofactor for?

A

carboxylation rxns:

  • pyruvate carboxylase (pyruvate (3C) –> OA (4C)) - used in gluconeogenesis
  • acetyl-CoA carboxylase (acetyl-CoA (2C) –> malonyl-CoA (3C)) - used in FA synthesis
  • propionyl-CoA carboxylase (propionyl-CoA (3C) –> methylmalonyl-CoA (4C)) - used to metabolize odd-chain FA, Val, Met, Ile, Thr (“VOMIT” pathway)
29
Q

B7 deficiency caused by? causes?

A

by avidin in egg whites or AB use

causes dermatitis, alopecia, enteritis; also fasting hypoglycemia (loss of pyruvate carboxylase)

30
Q

deficiency of B9 seen in?

A

alcoholics and pregnant pts

also w/ several drugs (phenytoin, sulfonamides, MTX, TMP)

31
Q

B9 function =?

A

converted to THF = coenzyme for 1C transfer/methylation rxns

impt for synth/repair of DNA and synth of nitrogenous bases in DNA + RNA

32
Q

B12 function?

A

cofactor for:

  • homocysteine methyltransferase (untraps inactive folate from storage [N5-methyl-THF])
  • methylmalonyl-CoA mutase (part of “VOMIT” pathway)
33
Q

deficiency of vit B12 seen w/?

A
  • malabsorption (enteritis, sprue, Diphyllobothrium latum)
  • lack of intrinsic factor
  • absence of terminal ileum (Crohn’s disese)
34
Q

labs show what in B12 def?

A

increased methylmalonic acid and homocysteine levels

35
Q

SAM and methionine regen depend on?

A

vit B12 and folate

36
Q

4 functions of vit C?

A
  • antioxidant
  • facilitate iron absorption by keeping in in reduced (Fe2+) state
  • nec for hydroxylation of proline and lysine in collagen synth
  • nec for dopamine-beta-hydroxylase (converts dopamine –> NE)
37
Q

vit D deficiency seen in patients that:

A
  • breast feed

- have dark skin

38
Q

vit E function?

A

protect RBCs and membrane lipids from ROS

39
Q

vit E deficiency?

A
  • hemolytic anemia (bc increased fragility of RBCs)
  • (proximal) muscle weakness
  • ***posterior column and spinocerebellar tract demyelination (mimics Friedrich’s ataxia; ataxia, dysarthria, loss of proprioception/vibratory sense)
  • decrease serum phospholipids and cause infertility
40
Q

vit E tx for?

A

abetalipoproteinemia

41
Q

vit E excess?

A 
hemorrhagic stroke (in adults)
necrotizing enterocolitis (in infants)
42
Q

vit K function

A

gamma-carboxylation of glutamic acid residues (put another COO- group)

43
Q

vit K deficiency seen in pts that?

A
  • breast feed

- after prolonged use of broad spectrum AB or phenytoin (wipe out intestinal gut flora)

USMLE Step 1 Random Facts (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions