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Flashcards in Nutrition Deck (38):
1

Water Soluble Vitamins that wash out easily?

All but B12 and folate which are stored in liver

2

B complex deficiencies result in

Dermatitis, Glossitis, Diarrhea

3

VitA
General function
Physiological role
Developmental role
Role in cancer
Use as a medication
Where is it found?

Antioxidant
Constituent of visual pigments (retinal)
Essential for normal differentiation of epithelial cells into specialized tissue (pancreatic cells, mucus-secreting cells)
Prevents squamous metaplasia
Used to treat measles, AML (subtype M3), wrinkles and acne
Found in liver and leafy vegetables

4

VitA
Deficiency
Excess

Night blindness and dry skin
Arthritis, Fatigue, Headache, Skin changes, Sore Throat, Alopecia, Teratogenic (cleft palate, cardiac abnormalities)

5

VitB1
Name
Enzymatic role

Thiamine
Part of Thiamine PyroPhosphate (TPP), a cofactor for decarboxylation reactions: "ATP Branch"
Pyruvate dehydrogenase (Glycolysis, TCA cycle), α-ketoglutarate dehydrogenase (TCA cycle), Transketolase (HMP shunt), Branched-chain AA dehydrogenase

6

VitB1 Deficiency
PathoPhys
What worsens it?
Which tissues affected?
Context
Names

Impaired glucose breakdown --> ATP Depletion worsened by glucose infusion
Highly aerobic tissue (brain and heart) affected first
Malnutrition or Alcoholism
Wernicke-Korsakoff, Beriberi

7

Wernicke-Korsakoff
Deficiency
Region damaged
Presentation

VitB1
Confusion, Ophthalmoplegia, Ataxia + Confabulation, Personality changes, Memory loss
Damage to medial dorsal nucleus of Thalamus, Mammillary bodies

8

Dry Beriberi
Deficiency
Presentation

VitB1
Polyneuritis, Symmetrical muscle wasting

9

Wet Beriberi
Deficiency
Presentation

VitB1
High output cardiac failure (Dilated Cardiacmyopathy), Edema

10

VitB2
Name
Function
Deficiency

Riboflavin
Cofactor in oxidation and reduction (FADH2). FAD and FMN are derived from B2 and yield 2 ATPs
"2 Cs of B2"
Cheilosis and Corneal vascularization

11

VitB3
Name
Function
Derived from...
Synthesis requires...
Deficiency
Excess
Used as treatment for...

Niacin
Constituent of NAD+ and NADP+ used in RedOx reactions to produce 3 ATP (B3 --> 3 ATP)
Derived from Tryptophan
Synthesis requires VitB6 and VitB2
Glossitis, Pellagra
Facial flushing due to pharmacologic doses for treatment of hyperlipidemia

12

Pellagra
Causes
Presentation

Hartnup Disease (↓ Tryptophan absorption), Malignant Carcinoid Syndrome (↑ Tryptophan metabolism), INH (↓ VitB6), VitB3 deficiency
Diarrhea, Dermatitis, Dementia

13

VitB5
Name
Function
Deficiency

Pantothenate "PENTOthenate"
Essential component for CoA and Fatty Acid Synthase
Dermatitis, Enteritis, Alopecia, Adrenal insufficiency

14

VitB6
Name
What is it converted into?
Kind of reactions it is involved with?
What molecules does it help synthesized?
Deficiency
What can cause it?

Pyridoxine
Converted into Pyridoxal Phosphate
Cofactor for Transamination, Decarboxylation, Glycogen phosphorylase
Synthesizes Crystathionine, Heme, Niacin, Histamine, Neurotransmitters (5HT, Epi, NE, GABA)
Convulsions, Hyperirritability, Peripheral neuropathy, Sideroblastic Anemia (impaired hemoglobin synthesis and iron excess)
INH or oral contraceptives can lead to it?

15

VitB7
Name
What kind of reactions
Enzymes
Deficiency
What causes it?

Biotin
Cofactor for Carboxylation enzymes that add 1 carbon group
Pyruvate carboxylase, Acetyl-CoA carboxylase, Propionyl-CoA carboxylase
Rare, Dermatitis, alopecia, enteritis
Caused by antibiotics or ingestion of raw eggs

16

BitB9
Name
What is it converted into?
What kind of reactions?
What does it synthesize
Where is it found?
Where is it stored in the body?

Folic Acid
THF
Coenzyme for 1 carbon transfer/methylation
Nitrogenous bases in DNA and RNA
Leafy vegetables
Small reserve pool stored in liver

17

VitB9 deficiency
What happens?
Frequency
What can cause it?
When and why is it given as a treatment

Macrocytic, Megaloblastic anemia, No neurological symptoms (as opposed to B12)
Most common deficiency in US
Alcoholism, Pregnancy, Phenytoin, Sulfonamides, MTX
Given to prevent neural tube defects in early pregnancy

18

VitB12
Name
Function
Where is it found?
What synthesizes it?
Storage?

Cobalamin
Cofactor for homocysteine methyltransferase (transfers CH3 groups as methylcobalamin and methylmalonyl-CoA mutase)
Found in animal products
Synthesized by microorganisms
Very large reserve pool (several years) stored in liver

19

VitB12 Deficiency
Presentation
Etiology
Test

Macrocytic Megaloblastic anemia, Hypersegmented PMNs, Neurological symptoms (paresthesia) due to abnormal myelin. Prolonged deficiency leads to irreversible nervous system damage
Malabsorption (sprue, enteritis, Diphyllobothrium latum), Lack of IF (pernicious anemia, gastric bypass surgery), Absence of terminal ileum (Crohn's disease)
Schilling test to detect etiology of the deficiency

20

VitB12 Reactions

Homocysteine + THF-CH3 --> [Homocysteine MethylTransferase w/ B12] --> Methionine + THF
Methionine gives CH3 for anabolic reactions
THF ->->-> dTMP pyrimidines
Odd # fatty acids --> Methylmalonyl-CoA --> [B12] --> Succinyl-CoA

21

VitB6 Reactions

Homocysteine ->->-> [B6] --> Cysteine
Succinyl-CoA --> [B6] --> Hb

22

Combined VitB12 and VitB6 Reactions

Odd # fatty acids --> Methylmalonyl-CoA --> [B12] --> Succinyl-CoA --> [B6] --> Hb

23

S-Adenosyl-Methionine
What is it made of?
What is its function
Basic Reaction
Regeneration requires
What reaction in neurons requires it?

ATP + Methionine
Transferes methyl units
Methionine + ATP --> SAM --> CH3 (for anabolic pathways) + Homocysteine
Regeneration requires B12 and Folate
Required for conversation of NE to Epi

24

VitC
Name
Function
Where is it found?

Ascorbic Acid
Antioxidant, Facilitate iron absorption by keeping iron in reduced Fe2+ state
Necessary for hydroxylation of proline and lysine in collagen
Necessary for Dopamine-β-Hydroxylase to convert DA into NE
Found it fruits and Vegetables

25

VitC
Deficiency
Excess

Weakened immune response, Scurvy due to collagen synthesis defect (swollen gums, bruising, hemarthrosis, anemia, poor wound healing)
Nausea, Vomiting, Diarrhea, Fatigue, Sleep Problems, and Risk of Iron Toxicity in predisposed individuals (transfusions, hemochromatosis)

26

VitD
Names with Source
Storage form
Active form

D2 - Ergocalciferol - ingested from plants
D3 - Cholecalciferol - consumed in milk, sun exposure
25OH D3 is storage form
1,25, OH2 D3 is active form

27

VitD
Function
Deficiency
Excess

Intestinal absorption of Ca and PO4, Increased bone mineralization
Rickets in children, Osteomalacia in adults,
HypoCa tetany. Decreased VitD in dark skinned pts.
HyperCa, Hypercalcinuria, loss of appetite, stupor. Seen in Sarcoidosis

28

VitE
Function
Deficiency

"E is for Erythrocytes"
Antioxidant (protects erythrocytes and membranes from free radical damage)
Fragile erythrocytes leading to hemolytic anemia. Muscle weakness, posterior column and spinocerebellar tract demyelination

29

VitK
Function
What synthesizes it?
What enzymes are VitK dependent?
VitK antagonist
Deficiency results in...
What causes deficiency?
When is it used as a medicine?

Catalyzes γ-carboxylation of glutamic acid residues on various proteins of blood clotting
Synthesized by intestinal flora
II, VII, IX, X, Proteins C and S
Warfarin --/ VitK
Neonatal hemorrhage with ↑ PT and ↑ aPTT but normal bleeding time
Infancy (because of sterile intestines) or broad spectrum antibiotics
Given to neonates because not in breast milk and prevents hemorrhage

30

Zinc
Function
Deficiency
Predisposes pts to...

Enzyme activity. Zn fingers in transcription factors
Delayed wound healing, Hypogonadism, ↓ adult hair, Dysgeusia, Anosmia
Predispose to Alcoholic Cirrhosis

31

Ethanol Hypoglycemia

1. EtOH metabolism leads to ↑ NADH/NAD ratio in liver
2. When NADH high, Pyruvate --> Lactate, Oxaloacetate --> malate
3. This leads to inhibition of gluconeogenesis and stimulates Fatty Acid Synthesis
4. Hypoglycemia and Hepatic Fatty Change
5. Overproduction of lactate --> acidosis
6. Depletion of oxaloacetate shuts down the TCA cycle, shunting acetyl-CoA into ketone production
7. Excess malate ↑ NADPH and thus fatty acid synthesis

32

Names of malnutrition syndromes

Kwashiorkor and Marasmus

33

Kwashiorkor
Lack of what?
Presentation
Classic patient

Protein malnutrition
"MEAL" Malnutrition, Edema, Anemia, Liver
Skin lesions, edema, Liver malfunction (fatty change due to ↓ apolipoprotein synthesis)
Small child with a swollen belly

34

Marasums
What is it?
Presentation

Energy malnutrition
Tissue and muscle wasting, loss of subcutaneous fat, edema

35

EtOH Metabolism
Pathway
Limiting reagent
Kinetics

Cyto:
EtOH + NAD --> [Alcohol Dehydrogenase] --> Acetaldehyde + NADH
Mito:
Acetaldehyde NAD --> [Acetaldehyde Dehydrogenase] --> Acetate + NADH
NAD is limiting reagent
Zero-Order Kinetics

36

Fomepizole
MoA
Use

Inhibits Alcohol Dehydrogenase
Antidote for methanol or ethylene glycol poisoning

37

Disulfiram
MoA
Use
What does it produce

Inhibits Acetaldehyde Dehydrogenase
Alcoholism
Produces Hangover Symptoms

38

Only vitamins not in breast milk?

D and K