Exam - Vitamin B12 Flashcards

1
Q

supplement label

A

helps produce red blood cells

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2
Q

what is another name for Vit B12

A

cobalamin

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3
Q

what is Vit B12 a generic term for

A

a group of corrinoids

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4
Q

why are the compounds called corrinoids

A

they have a corrin nucleus that contains cobalt

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5
Q

what is the most complex vitamin structure

A

B12 - discovered last because of this

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6
Q

what produced B12

A

bacteria only

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7
Q

where is B12 present

A

animal products

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8
Q

who is at risk for a deficiency

A

vegetarians/vegans

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9
Q

is there a plant provitamin B12

A

no

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10
Q

what does a B12 deficiency cause

A

functional folate deficiency
neurological problems

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11
Q

is there an upper limit

A

no

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12
Q

2 leading causes of Vit B12 deficiency

A

not enough in diet
improper absorption due to defects in intrinsic factor

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13
Q

how are deficiencies shown in blood

A

in the form of megaloblastic anemia

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14
Q

where is folate critically important

A

in dividing cells that support the production of specialized cells that form the neural tube (early pregnancy)

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15
Q

what can folate deficiencies leaf to

A

severe birth defects i.e neural tube defects

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16
Q

what is the neural tube in embryo

A

the CNS which becomes the spinal cord or brain

17
Q

what is a NTD

A

opening of spinal cord or brain

18
Q

what are the key players in single carbon metabolism

A

folate
vitamin B12
S-adenosyl methionine

19
Q

what can folate deficiency lead to

A

impaired DNA synthesis and repair
uracil misincorporation
megaloblastic anemia

20
Q

what is the folate trap when someone is B12 deficient

A

in single carbon metabolism, there is no SAM cycle because there is no B12 cofactor and N5-methyl THF cannot become THF

21
Q

what bypasses the folate trap

A

large doses of folate can hide a B12 deficiency - large doses can form N5-methyl THF in the gut so there is more folate going to liver to be converted into THF