B12/Folate Deficiencies

Question 1

other name for B12?

Answer 1

cobalamin

Question 2

other name for folate?

Answer 2

vitamin B9

Question 3

how do we obtain b12?

Answer 3

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

Question 4

how do we obtain folate?

Answer 4

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

Question 5

what’s wrong with a B12 deficiency?

Answer 5

b12 is crucial to folate synthesis

Question 6

whats wrong with a folate deficiency?

Answer 6

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

Question 7

how can you distinguish between a folate or B12 deficiency?

Answer 7

methylmalonic acids levels will only be elevated if B12 is deficient

Question 8

function of B12

Answer 8

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

Question 9

tests for B12 deficiency

Answer 9

decreased THF, increased HCY & MMA

Question 10

hematologic symptoms of B12/folate deficiency

Answer 10

megaloblastic anemia, low platelets, leukopenia

Question 11

dermatologic symptoms of B12/folate deficiency

Answer 11

rashes, hyperpigmentation, epithelial atrophy

Question 12

oral/GI symptoms of b12/folate deficiency

Answer 12

diarrhea, malabsorption, chelitis, glossitis

Question 13

neuropsychiatric symptoms of b12/folate deficiency

Answer 13

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

Question 14

what can mask symptoms of b12 deficiency?

Answer 14

supplementing folate

Question 15

intrinsic factor

Answer 15

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

Question 16

transcobalamin 2

Answer 16

transports cobalamin to cells

Question 17

R proteins

Answer 17

protect B12 from degradation in the stomach

Question 18

where is folate absorbed?

Answer 18

jejunum

Question 19

where is b12 absorbed?

Answer 19

ileum

Question 20

where is iron absorbed?

Answer 20

duodenum

Question 21

Lab results for B12 deficiency

Answer 21

increased MMA & HCY, decreased reticulocytes

Question 22

cause of B12 deficiency if B12 injection is curative?

Answer 22

nutritional deficiency

Question 23

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

Answer 23

gastric pernicious anemia

Question 24

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

Answer 24

abnormal bacterial growth in intestines

Question 25

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

Answer 25

pancreatic insufficiency

Question 26

pernicious anemia

Answer 26

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

Question 27

megaloblastic anemia

Answer 27

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

Question 28

types of microcytic anemia

Answer 28

iron deficiency, thalassemia, anemia of inflammation

Question 29

types of normocytic anemia

Answer 29

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

Question 30

types of macrocytic anemia

Answer 30

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

Question 31

causes of megaloblastic anemia

Answer 31

B12, folate deficiency, antimetabolites

Question 32

morphology of megaloblastic anemia

Answer 32

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

Question 33

problems that lead to hyper segmented neutrophils

Answer 33

megaloblastic anemia & iron deficient anemia

Question 34

how severe are the neuropsychiatric pathologies associated with b12 deficiency?

Answer 34

irreversible if b12 deficient for >6mos

Question 35

effects of b12 deficiency on myelin

Answer 35

elevated levels of MMA destabilize myelin

Question 36

subacute combined degeneration of spinal cord

Answer 36

progressive onset due to loss of myelination from b12 deficiency.

Question 37

treatment for b12 deficiency

Answer 37

parenteral b12, IM B12 for more severe cases

Question 38

treatment for pernicious anemia

Answer 38

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

Question 39

treatment for folate deficiency

Answer 39

oral folate