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Folic
acid or folate as it is also called, is found in
green leafy vegetables.
Folate from vegetables is about 40-50%
less bioavailable than synthetic folic acid,
which is almost 100% bioavailable.
After it is absorbed by the body it is
converted into tetrahydrofolate.
Tetrahydrofolate based coenzymes play a
major role in intracellular (within the cell)
metabolism. Folic acid reduces errors to DNA and
prevents replication errors.
Folate deficiency disturbs the cycling of
the cells and induces and increases the rate of
cell aptopsis (cell death).
It is involved in the metabolism of
homocysteine (high levels cause inflammation).
Low levels of Folate are associated with
an increase plasma homocysteine levels.
High levels of homocysteine (hyperhomocysteinemia)
is a risk factor for coronary, cerebral, and
peripheral atherosclerosis; recurrent
thromboembolism; deep vein thrombosis;
myocardial infarction; and ischemic stroke.
Why
are high homocysteine plasma levels a risk
factor for certain diseases?
The mechanism of action isn't fully
understood, but it might include vascular
endothelial cell damage(deterioration of the
blood vessels), impaired endothelium dependent
vasodilation (blood vessels don't dilate
properly) due
to reduced nitric oxide activity, arterial
stiffening due to increase in oxidation(arteries
become stiff) and arterial deposition of low
density lipoproteins (LDL cholesterol deposits
in the lining of the artery), increase of
platelet adhessiveness (blood thickens becomes
less viscous), and activation of the clotting
cascade (increase in clots formed in the
vessels).
All
vitamins are essential and play important roles
in metabolic pathways.
Folic acid is an especially important
vitamin. The
following description of it's role may at times
be a bit technical, but it is important in
helping you to understand just how imperative it
is to ensure that you are not deficient in folic
acid or in any steps along the way.
Homocysteine
is metabolized via two pathways.
One is called "remethylation"
the other "transsulfuration".
remethylated
Homocystein----------------------->
methionine
This
reaction is facilitated by folate and Vitamin
B12 (cofactors).
Without these two cofactors, this
processes would not take place and homocystein
would remain in tact, thus increase homocystein
levels in blood stream.
There
is another factor that can impede this process.
Some people homozygous fo the mutations
of the gene MTHFR(5,10 methyltetrahydrofolate
reductase).
This is an enzyme involved in the
conversion of homocysteine to methionine.
When you are homozygous for this gene
most often you need to take higher doses of
folate, usually 1mg per day.
Transsulfuration
usually occurs after an individual ingests a
meal high in animal protein (a methionine load).
via
pyrodoxine(vit B6)
Homocystein-------------------------->cystathionine------------------------------->cysteine
Deficiency
of pyrodoxine impairs the pathway raising
homocysteine levels as well.
In addition to folic acid, vitamin B12
and B6 are important for successful conversion
of homocysteine.
What
does all of this mean and why is it important to
health? Well
plays an important role in pregnancy and the
healthy development of the fetus.
Low levels are associated with neural
tube defects in the fetus.
Low
levels might play a role in Alzeihmers Disease.
It seems to be associated with atrophy of
the cerebral cortex.
Homocysteine
is thought to be neurotoxic, causing DNA damage
and cell apoptosis which is associated with
functional and mental deterioration in the
elderly.
Folic
acid deficiency is common in people with
depression.
Low levels have been linked to poor
response to antidepressant treatment.
Folic
acid is required for the conversion of
homocysteine------->SAMe.
SAMe in turn is associated with an
increase in serotonin turnover, increase in
dopamine, and norepinephrine levels.All of these
play a role in mood.
When
you go to the pharmacy, you will find that there
are individual B vitamins and then there are
products that provide a combination of all B
vitamins. he
previous pathways might have given you a clue as
to why these B vitamin complexes are so popular.
Various
B vitamins played a key role in these
homocysteine conversion pathways.
Where folic acid is the work horse, the
other B vitamins are its helpers.
Just like Cinderella was the hard worker
of the family she couldn't have made it to the
ball without her little helpers.
By working together they were able to
stop the evil stepmother (homocysteine) from
getting her way.
Folic
acid supplementation is helpful in treating and
or preventing the following conditions:
End-stage renal disease,
hyperhomocysteinemia (11 micromoles/L
or higher), methotrexate toxicity, neural
tube defects, breast cancer, colorectal cancer,
depression, Alzheirmers, risk of cervical
cancer, cognitive function, infertility, and
restless leg syndrome.
Typical
doses are:
250mcg-1000mcg/Day
Severe
disorders and under medical
supervision(1000-5000mcg/Day)
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