Folate Flashcards
Vitamin _____
____ soluble
Required for formation of
fxns as
Found in nature as ___, therapeutically as ______
B9
water
hematopoietic cells
coenzyme in met of nucleic acids and AA
folate, folic acid
Foods rich in folate A B S D B L F
avg daily intake
food can be depleted of folate via
Asparagus, brocoli, spinach, dark green vegetables, beans, legumes, fortified cereals/grains
exceeds requirement
cooking (folic acid more stable)
Absorbed in
taken up from
there it is
usually is
intestinal mucosa via AT
portal circulation by liver
metabolized/retained and released in blood/bile
bound to protein
Acts as a ____, in transfer of
Naturally occuring reduced form of folate
to become fxnal, must be
folate is a
methylation cycle
coenzyme, single carbon units for purine/pyramidine synth (DNA/RNA rep)
5methyltetrahydrofolate (5MTHF)- most abundant folate in plasma
reduced to FH4 (met active in all cells)
coenzyme in methionine synth in generating FH4
regenerates FH4
Folate loss occurs in anatomic areas
lack of intake dec
results in
elevates
urine, skin, bile (must be replenished via diet)
activity of methylation cycle
dec cell division (worst in rapidly dividing cells- RBC/BM/GI tract)
plasma homocysteine (indicates folate def)
Def leads to
results in
presentation similar to
in contrast
Pt present w
Smear findings may also show
megaloblastic anemia due to impaired NA metabolism
nuclear abnormalities of myeloid/erythroid precursors
B12 def
no neuropathy unless severe/prolonged def
anemia/asx w macrocytosis
hypersegmented neutrophils and pancytopenia
Folate def occurs in
can occur in infants fed exclusively
pregnant women at risk bc
during lactation
people w limited diet (alcoholics) or malabsorptive cx (celiac)
goat milk (dec folate)
pregnancy greatly inc folate requirements (esp in rapid fetal growth)
losses of folate in milk also inc folate req
Pt with folate def diet can become folate def
In pregnancy, inc risk of fetal neural tube defects as
between 21 and 27 days post conception
must have
to reduce risk, women of childbearing age should
specifically ____, bc
in weeks/mnths
folate dec
neural plate closes, forming spinal cord and cranium
adequate folate at this time
take 400 mg of FA daily
FA, more bioavailable
Methotrexate interferes w
this will
all pt on methotrexate needs
measuring Folate is
detect with
cellular utilization of FA
dec IC FH4, affecting metabolic pathways including purine/pyramidine synthesis
FA
unreliable, rapid inc after meal
elevated homocysteine
Toxicity
excess intake of supps induces
excess folate can mask
people at risk for B12 def (vegans/PA)
no AE from foods
onset/progression of neuro comps in people w B12 def
b12 def, resulting in progressive neuro damage
should not consume excess folate
