First Aid Biochem - Nutrition Flashcards Preview

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Flashcards in First Aid Biochem - Nutrition Deck (46)
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1
Q

fat soluble vitamins

A

A,D,E,K
- toxicity with these vitamins is more common than with water-soluble vitamins due to accumulation of these vitamins in fat.

2
Q

water soluble vitamins

A
B1
B2
B3
B5
B6
B7
B9
B12
C
3
Q

B1

A

thiamine: TPP

4
Q

B2

A

riboflavin: FAD, FMN

5
Q

B3

A

niacin: NAD+

6
Q

B5

A

pantothenic acid: CoA

7
Q

B6

A

pyridoxine: PLP

8
Q

B7

A

biotin

9
Q

B9

A

folate

10
Q

B12

A

cobalamin

11
Q

C

A

ascorbic acid

12
Q

Storage of water soluble vitamins

A

all wash out from the body easily except for B12 and B9.
B12 - stored in lvier for about 3 - 4 years
B9 - stored in liver for about 3 - 4 months

13
Q

Vitamin A function

A

antioxidant, constituent of visual pigment, used in treatment of measles and AML subtype M3, essential for normal differentiation of epithelial into specialized tissue.
topically used for wrinkles and acne
found in liver and leafy vegetables

14
Q

Vitamin A deficiency

A

night blindness (nyctalopia), dry, scaly skin (xerosis cutis), corneal degeneration (keratomalacia)

15
Q

Vitamin A excess
acute toxicity
chronic toxicity

A

acute toxicity nausea, vomiting, vertigo, and blurred vision
chronic toxicity alopecia, dry skin, pseudotumor cerebri

teratogenic: cleft palate, cardiac abnormalities, negative pregnancy test and 2 forms of contraception required for acutane (isotretinoin) prescription.

16
Q

Vitamin B1 function

A

in thymine pyrophosphate (TPP) a cofactor for several dehydrogenase enzyme reactions

  • pyruvate dehydrogenase (links glycolysis to the TCA cycle)
  • alpha-ketoglutarate dehydrogenase (TCA cycle)
  • transketolase HMP shunt
  • branched-chain ketoacid dehyrdrogenase
17
Q

Vitamin B1 deficiency

A

impaired glucose breakdown (THIAMINE before IV glucose) –> ATP depletion
highly aerobic tissue affected first i.e brain and heart

18
Q

Wernicke-Korsakoff syndrome

A
- Thiamine B1 deficiency 
classic triad: 
confusion 
ophthalmoplegia 
ataxia 
\+ confabulation, personality change
19
Q

BeriBeri Syndrome

A
  • Thiamine B1 deficiency
    Dry Beriberi - polyneuritis, symmetrical muscle wasting
    Wet beriberi - high-output cardiac failure, edema
20
Q

Vitamin B2 function

A

Riboflavin. component of flavins in FAD and FMN. Used as cofactors in redox reactions.

21
Q

Vitamin B2 deficiency

A

Riboflavin. Cheilosis (inflammation of the lips, scaling and fissures at the corners of the mouth), Corneal vascularitzation.
+ stomatitis, painful red tongue with sore throat.

Cheilosis and Corneal, the 2 C’s of B2.

22
Q

Vitamin B3 function

A

Niacin. constituent of NAD+, NADP+ used in redox reactions. Derived from tryptophan. Synthesis requires B2 and B6. Used in the treatment of dyslipidemia, lowers VLDL and raises HDL.

23
Q

Vitamin B3 deficiency

A

Niacin.
Glossitis.
Severe deficiency leads to pellagra, can be caused by:
- Hartnup disease (own card)
- malignant carcinoid (increased tryptophan metabolism)
- isoniazid (decreases vitamin B6)

Symptoms of pellagra:
- Diarrhea, Dementia (and hallucinations), Dermatitis(C3/C4 dermatome, broad collar rash)

24
Q

Hartnup Disease

A

autosomal recessive deficiency of neutral amino acid (i.e. tryptophan) transporters in the proximal renal tubular cells and on enterocytes
–> neutral amino acuduria
–> decrease tryptophan for conversion to niac in
–> pellagra like symptoms
Tx: is high protein diet and nictonic acid

25
Q

Vitamin B5 function

A

pantothenic acid. an essential component of coenzymeA.

26
Q

Vitamin B5 deficiency

A

dermatitis, enteritis, alopecia, adrenal insufficiency.

27
Q

Vitamin B6 function

A

pyridoxine. converted to PLP (pyridoxal phosphate), a cofactor used in transamination (i.e. ALT, AST), decarboxylation reactions, glycogen phosphorylase.
Used in the synthesis of niacin and neurotransmitters including norepinephrine, epinephrine, serotonin, dopamine, GABA.

28
Q

Vitamin B6 deficiency

A

convulsions, hyperirritability, peirpheral neuropathy, deficiency is inducible by isoniazid and oral contraceptive, sideroblastic anemia due to impaired hemoglobin synthesis and iron excess.

29
Q

Vitamin B9 function

A

folate. converted to THF, a coenzyme for 1 carbon transfer/methylation reactions. IMPORTANT for the synthesis of nitrogenous bases in DNA and RNA.

found in leafy green vegetables, absorbed in jejunum. 3-4 month reserve in the liver.

30
Q

Vitamin B9 deficiency
signs/symptoms
labs
causes

A

folate. macrocytic megaloblastic anemia, hypersegmented PMNs, glossitis, NO NERUOLOGIC symptoms (this is in contrast to B12)

Labs: increase homocysteine (normal methymalonic acid also in contrast to B12).

MOST COMMON vitamin deficiency in the united states seen in alcoholism and pregnancy.
Can be caused by certain drugs: phenytoin, sulfonamides, methotrexate.

31
Q

Vitamin B12

A

cobalamin.

32
Q

Vitamin B12 function

A

cobalamin. cofactor for methionine synthase (transfers CH3 groups as methylcobalamin) and methylmalonyl-CoA mutase.

Found in animal products. Very large reserve pool in the liver.

  • Note anti-intrinsic factor antibodies are diagnostic for pernicious anemia.
33
Q

Vitamin B12 Deficiency
signs/symptoms
causes
labs

A

macrocytic, megaloblastic anemia, parethesias, degeneration of dorsal column, lateral corticospinal tract, and spinocerebellar tracts.

cobalamin. Deficiency is caused usually by malabsorption (sprue, enteritis), lack of intrinsic factor (pernicious anemia, gastric bypass surgery), absence of terminal ileum (i.e. after surgical resection for crohn disease), or insufficient intake (vegan).

increased homocysteine and methylmalonic acid.

34
Q

Vitamin C function

A

ascorbic acid.

35
Q

Vitamin C function

A

ascorbic acid. antioxidant. also facilitates iron absorption by reducing it to Fe2+ state.
it is necessary for hydroxylation of proline and lysine in collagen synthesis.
necessary for dopamine b-hydroxylase which converts dopamine to NE.

36
Q

Vitamin C deficiency

A

Scurvy. Swollen gums, bruising, petechiae, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhages. “corkscrew hair”.
weakened immune response.
Vitamin C causes sCurvy due to a Collagen synthesis defect.

37
Q

Vitamin D function

sources

A

D2 = ergocalciferol ingested in plants.
D3 = cholecalciferol consumed in milk, formed in sun exposed skin (stratum basale)
25-OH D3 - storage form
1,25-OH D3 - calcitriol, active form

  • function: increases intestinal absorption of calcium and phosphate, increased bone mineralization at low levels, increased bone resorption at higher levels.
38
Q

Vitamin D deficiency

A

Rickets in children, bone pain deformity.
Osteomalacia in adults (bone pain and muscle weakness)
hypocalcemic tetany

39
Q

Vitamin D excess

A

hypercalcemia, hypercalciuria, loss of appetite, stupor. Seen in granulomatous disease (there is increased activation of Vitamin D by epitheliod macrophages).

40
Q

Vitamin E function

A

antioxidant. protects RBCs and membranes from free radical damage.

41
Q

Vitamin E deficiency

A

Hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract demyelination.

  • Neurologic findings may be similar to B12, but there will not be associated megaloblastic anemia, hypersegmented neutrophils, or increased serum methymalonic acid.
42
Q

Vitamin K function

A

Cofactor for gamma-carboxylation of glutamic acid residues on various proteins required for blood clotting. Synthesized by intestinal flora.

  • necessary for maturation of the clotting factors 2,7,9,10 as well as protein C and protein S. Warfarin is a vitamin K antagonist.
43
Q

Vitamin K deficiency

A

Neonatal hemorrhage can present with increased PT and increased aPTT but normal bleeding time (neonates have sterile intestine and lack bacterial flora that make vitamin K, coagulation factors cannot mature). Hemorrhage from vitamin K deficiency can also occur after prolonged use of antibiotics.

  • NOTE vitamin K is not in breast milk. neonates are given vit K injection to prevent hemorrhage in newborn.
44
Q

Zinc function

A

an essential mineral for the activity of >100 enzymes.

45
Q

Zinc deficiency

A

delayed wound healing, hypogonadism, decrease adult hair (axillary, facial, pubic), dysgeusia, anosmia, acrodermatitis enteropathica

46
Q

Kwashiorkor
cause
presentation

A

protein malnutrition resulting in skin lesions. edema (due to decreased plasma oncotic pressure), liver malfunction (fatty changes due to decresed apolipoprotein syntehsis).

clinical picture is small child with swollen abdomen.