B12/Folate Deficiencies Flashcards Preview

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Flashcards in B12/Folate Deficiencies Deck (39):
1

other name for B12?

cobalamin

2

other name for folate?

vitamin B9

3

how do we obtain b12?

can't synthesize it, so it must come from diet (animal proteins, dairy) --> vegans need supplements

4

how do we obtain folate?

we synthesize it and obtain it from vegetables, nuts, dairy, meat

5

what's wrong with a B12 deficiency?

b12 is crucial to folate synthesis

6

whats wrong with a folate deficiency?

without it, body cant synthesize thymine and therefore cant synthesize DNA

7

how can you distinguish between a folate or B12 deficiency?

methylmalonic acids levels will only be elevated if B12 is deficient

8

function of B12

cofactor for tetrahydrofolate (THF) production, for methionione production from homocysteine (HCY), & for succinyl coA from methylmalonyl (MMA)

9

tests for B12 deficiency

decreased THF, increased HCY & MMA

10

hematologic symptoms of B12/folate deficiency

megaloblastic anemia, low platelets, leukopenia

11

dermatologic symptoms of B12/folate deficiency

rashes, hyperpigmentation, epithelial atrophy

12

oral/GI symptoms of b12/folate deficiency

diarrhea, malabsorption, chelitis, glossitis

13

neuropsychiatric symptoms of b12/folate deficiency

neural tube defects, ataxia, paresthesias, megalobastic madness, depression blindness

14

what can mask symptoms of b12 deficiency?

supplementing folate

15

intrinsic factor

secreted from gastric parietal cells. promotes absorption of cobalamin in ileum

16

transcobalamin 2

transports cobalamin to cells

17

R proteins

protect B12 from degradation in the stomach

18

where is folate absorbed?

jejunum

19

where is b12 absorbed?

ileum

20

where is iron absorbed?

duodenum

21

Lab results for B12 deficiency

increased MMA & HCY, decreased reticulocytes

22

cause of B12 deficiency if B12 injection is curative?

nutritional deficiency

23

cause of B12 deficiency if injection doesn't cure & IF infusion does

gastric pernicious anemia

24

cause of B12 deficiency if B12/IF infusions don't work, but antibiotics do

abnormal bacterial growth in intestines

25

cause of B12 deficiency if B12/IF/antibiotics don't work, but addition of pancreatic enzymes does

pancreatic insufficiency

26

pernicious anemia

autoimmune condition that destroys gastric parietal cells so that IF isn't available for binding and absorption.

27

megaloblastic anemia

macrocytic anemia caused by impaired DNA synthesis and nuclear/cytoplasmic maturity imbalance (nucleus is less mature). shortened life

28

types of microcytic anemia

iron deficiency, thalassemia, anemia of inflammation

29

types of normocytic anemia

acute blood loss, bone marrow failure, renal disease, sickle cell disease

30

types of macrocytic anemia

B12/folate deficiency, autoimmune hemolytic (pernicious) anemia, hypothyroidism, antimetabolites

31

causes of megaloblastic anemia

B12, folate deficiency, antimetabolites

32

morphology of megaloblastic anemia

RBCs with mature pink cytoplasm, with dark condensed nucleus. hyper segmented neutrophils.

33

problems that lead to hyper segmented neutrophils

megaloblastic anemia & iron deficient anemia

34

how severe are the neuropsychiatric pathologies associated with b12 deficiency?

irreversible if b12 deficient for >6mos

35

effects of b12 deficiency on myelin

elevated levels of MMA destabilize myelin

36

subacute combined degeneration of spinal cord

progressive onset due to loss of myelination from b12 deficiency.

37

treatment for b12 deficiency

parenteral b12, IM B12 for more severe cases

38

treatment for pernicious anemia

oral B12 in high dose following parenteral replacement (can absorb some due to laws of mass action)

39

treatment for folate deficiency

oral folate