vitamin in adulthood quick review table

Question 1

B1 (thiamin) RDA based on

Answer 1

1) amount needed to maintain transketolase activity within RBC (TPP)
2) without excess urinary excretion

Question 2

B2 (riboflavin) RDA based on

Answer 2

1) RBC glutathione reductase activity coefficient (FAD is a cofactor for this enzyme)
2) concentration of riboflavin in RBC
3) urinary riboflavin

Question 3

B3 (niacin) RDA based on

Answer 3

urinary excretion of metabolites

Question 4

B6 ( pyridoxine ) RDA based on

Answer 4

maintenance of adequate blood 5’pyridoxine phosphate levels

Question 5

folate RDA based on

Answer 5

RBC folate and blood homocystiene levels

Question 6

B12 RDA based on

Answer 6

maintenance of hematological status and b12 blood values

Question 7

biotin (B7) AI based on

Answer 7

population studies without signs of deficiency

Question 8

Choline AI based on

Answer 8

the prevention of liver damage assessed by serum alanine aminotransferase activity

Question 9

B5 ( pantothenic acid ) AI based on

Answer 9

adequate intake to replace urine excretion

Question 10

tryptophan may be converted to?/

Answer 10

niacin

Question 11

niacin expressed as

Answer 11

NEs

Question 12

which vitamins are mg/d

Answer 12

B1, B2, B3,B5 (AI), B6, Choline (AI), vit C, vit E

Question 13

which vitamins are ug/d

Answer 13

B12, folate, vit A, biotin(AI), vit K (AI)

Question 14

vit C RDA based on

Answer 14

1) maintains near optimal neutrophil concentration 2) min urinary excretion

Question 15

vit A RDA based on

Answer 15

based on the amount needed to maintain a body-pool size that will ensure adequate storage given a time period of low intake or stress

Question 16

Vit D RDA based on

Answer 16

based on health benefits associated with vit D status ( increases with age over 70 )

Question 17

vit E RDA based on

Answer 17

based on the correlation between H2H2 induced RBC lysis and blood a-tocoperol

• need to note that DRI is based on 2R sterioisoforms, in which the all race forms have 1/2 the activity of 2R

Question 18

vit K AI based on

Answer 18

based on representative dietary data on healthy individuals

Question 19

when figuring out choline RDA, liver damage is assessed by which enzyme

Answer 19

alanine aminotransferase

Question 20

the difference in how B5 and B7 AI are assessed

Answer 20

B5 is based on amount needed to replace urinary excretion, while B7 is based on population studies of healthy individuals without signs of deficiency

Question 21

commo marker for thiamine deficiency and why

Answer 21

the activity of trans-keto-lase. which is an enzyme in RBC that converts PPP back into glycolytic intermediates. Thiamine diphosphate (TPP) is required as a cofactor along with Mg+

Question 22

how does choline play a role in the homocysteine pathway

Answer 22

along with 5-met-TH4-folate, adequate choline is needed to get converted to betaine which is used to regenerate methionine from homocysteine