Folate revision questions - week 10

Question 1

Food sources

Answer 1

• green veges, liver, enriched cereals, legumes, oranges

Question 2

Absorption

Answer 2

• poly broken down to monoglutamates in GIT by folate conjugase for absorption (zinc dependent)
• folate monoglutamate absorbed by active transport in SI
• folic acid (supplements) - passive diffusion
• conversion to THFA in enterocytes for folate and liver for folic acid by dihydrofolate reductase

Question 3

transport

Answer 3

• circulates in many forms but 5-methyl THFA is main form

- converted back to polyglutamate in cell

Question 4

is the only water soluble vitamin with

Answer 4

significant storage

Question 5

Storage

Answer 5

liver

Question 6

EXcretion

Answer 6

urine and faeces

Question 7

Coenzyme form

Answer 7

tetrahydrofolic acid (THFA)

Question 8

main function

Answer 8

• coenzyme in DNA synthesis, homocysteine metabolism

Question 9

RDI

Answer 9

400ug

Question 10

UL

Answer 10

1000ug (based on masking B12 deficiency)

Question 11

toxicity

Answer 11

none

Question 12

deficiency

Answer 12

• megaloblastic macrocytic anemia

- in pregnancy - neural tibe defects e.g. spina bifida

Question 13

1ug of Dietary folate equivalent =

Answer 13

= 1ug food folate
= 0.5ug folic acid on empty stomach
= 0.6ug folic acid with meals