Folate Flashcards
folic acid is _____ form
monoglutamate, synthetic
folate is ____ form
polyglutamate, food
we absrb folate as ___
folic acid
enzymes called ____ remove all Glu except for 1 (folic acid)
conjugases
1 DFE=__mcg folic acid in food
0.6 (1.7x more available than folate in food)
1 DFE= __mcg folic with no food
0.5 (2x more available than food folate)
what is folacin?
term used for the total folate molecules without applying DFE
folate enters mostly as ___ with normal dietary amounts
5-methyl THF
THF has role in ___
DNA synthesis
dietary excess cause folate enter in as ___
DHF
methyl-THF –> THF reversible?
no
what is methyl trap?
in B12 deficiency, methyl not removed from methyl-THF so THF can’t be used for functions
rxn of methyl-THF to THF?
methyl-tHF donate methyl to B12 which donates methyl to homocysteine to make methionine
methyl trap can be overcome by ___
ingesting large amounts of folate
main symptom of folate deficiency?
megaloblastic anemia
how is B12 deficiency masked?
ingesting excess folate, HCY cannot –> MET
UL is based on?
prob of excess folate masking B12 deficiency
3 probs of folate deficiency?
megaloblastic/macrocytic anemia, neurl tube defects, hear disease/dementia/cancer
fortification of flour in USA and Canada, adding ____mcg/day
100
example of NDT?
spina bifida
for every 5mcmol/L increase in homocysteine, there is ___% increase in risk of heart disease
30-40
poor folate is connected with __ cancer
colon
why is increasing folate when after have cancer already, might cause ___ of DNA, causing greater cancer progression
hypermethylation
static measures of folate?
serum (rise rather quickly) , RBC (better)
what happens to tongue in folate deficiency
glossitis (red, painful, shiny smooth surface)
food sources folate
legumes, mushrooms, liver, tea, beer, green veg, citrus fruit, fortified white flour
secondary deficiency of folate?
drugs (alcohol, anticonvulsants), B12
RDA is __, EAR is ___
400; 320 DFE
UL for folate?
1 mg for folic supplements/fortified foods
genetic variation of MTHFR on position ___; homozygous for ____ instead of cytosine (alanine)
677; thymine (valine)
what is the functional measure of folate?
^plasma homocysteine if poor folate (not specific to folate->B6, B12)
