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What is Folic Acid
Folic acid. The name sounds like it might be dangerous,
a caustic acid substance and not good for health. But it
is actually a very important vitamin and therefore essential
to your life and your health. It is also the most commonly
deficient vitamin in Americans and the average American
diet provides only about half the RDA, the amount recommended
by the Food and Nutrition Board. Folic acid is found in
green leaves, such as spinach, asparagus, beans (legumes)
and especially in brewers yeast and liver. If you don't
like any of those foods, try eating butterfly wings for
an exotic source health food.
Deficiency of folic acid is an important cause of birth
defects, particularly spina bifida, a defect in the formation
of the lower back which leaves the spinal cord exposed.
Several studies have confirmed the value of folic acid in
preventing these "neural tube defects" and the
FDA now recommends that prospective mothers take folic acid
supplements because women are unlikely to obtain a sufficient
amount of folate to support a healthy pregnancy unless a
supplement is taken. If it were only to prevent birth defects,
I strongly recommend that all women of child-bearing age
take a folic acid supplement of at least 0.4 mg and preferably
twice that much on a regular basis.
Folic acid has many other actions that you need to know
about. This vitamin is especially important in patients
whose illness requires hospital care. Research reports indicate
that a third of the psychiatric patients and two thirds
of the medical patients in hospital are low in folic acid.
Deficiency is not necessarily due to poor diet. Intestinal
malabsorption and treatment with female hormones and birth
control pills also cause low folic acid levels. Anticonvulsant
therapy with Dilantin is most likely to block absorption
and interfere with conversion to the active form in the
brain and this can cause depression and loss of mental acuity,
which are responsive to folic acid treatment.
At menopause many women produce extra amounts of homocysteine,
an amino acid by-product of protein. Homocysteine is a powerful
solvent, capable of attacking collagen and hence weakening
all tissues, but especially blood vessels and bone. When
bones weaken they lose calcium, become porous, hence the
name, osteoporosis. Deficiency of folic acid (as well as
B12 and B6) causes increased homocysteine accumulation and
hence aggravates osteoporosis. Damage can be prevented by
folic acid supplements and this therapy may be indicated
even if folate blood levels are within the normal range.
As you can see, there is more to osteoporosis than just
calcium and there is more to folic acid than is revealed
by simple measurement of blood levels. Functional tests,
such as the presence of homocysteine, are actually more
revealing.
The main chemical function of folic acid is in transporting
a carbon atom in the form of a methyl group. This action
has been put to good use in treating victims of methyl alcohol
poisoning. A more common and therefore more important function
of folic acid is in the manufacture of nucleic acids, essential
for growth and repair in every cell in the body. Growing
cells need folic acid; hence deficiency causes anemia and
delays healing. Mature cells also need folic acid to assure
repair of nucleic acids that get damaged by carcinogens,
radiation and even by dietary oxidative by-products nucleic
acids.
Cancer cells also need folic acid in order to grow and
folic acid blockers, such as methotrexate, are sometimes
used to curtail cancer growth; a technique that works best
if folic acid, in turn, is used to promote healing in the
"rescue" strategy in cancer chemotherapy. Folic
acid has also been found effective against pre-cancerous
cervical dysplasia. It is so effective here that abnormal
cells can become normal again! Hence folic acid, along with
vitamin A and vitamin C, which share this action, should
be tried before resorting to surgical intervention.
Folic acid deficiency, even if temporary, has been found
to weaken the immune system for about three months after
since folate deficient lymphocytes do not recover function
but must be replaced by new cells. Nerve cells are affected
by folic acid in several ways. Methyl group transfer is
critical to the production of choline, which is essential
to repair cell membranes and in the production of acetylcholine,
a key neurotransmitter. Folic acid is also essential in
manufacture of catecholamine transmitters and in the removal
of their end products, thus balancing the action of neurotransmitters,
such as norepinephrine and epinephrine.
The RDA of folic acid is only 0.4 mg per day and doses
larger than 3 mg can be over-stimulating. Emotional tension,
irritability and headache can occur and there is a small
increase in the risk of seizures at intake above 5 mg per
day. On the other hand, large doses of folic acid are also
reported to increase the pain threshold, ie. to reduce pain.
Large doses of folic acid, up to 80 mg daily, were given
to 150 patients by Dr. Kurt Oster, who found that folic
acid inactivates an enzyme, xanthine oxidase, and thus reverses
damage to the blood vessel wall in atherosclerosis patients.
There were no bad reactions to these large doses in his
cases; however several studies point to danger in taking
folic acid supplements greater than 5 mg daily. One of my
patients had a seizure, a single episode of abrupt emotional
overactivity followed by loss of consciousness and stiffening
of the entire body, including tongue biting, which all came
on 3 hours after a single 10 mg dose of folic acid and after
a year of regular intake of about 1 mg daily. Two days later
his folic acid blood level was over twice the normal. After
stopping folic acid supplements, he is free of spells of
emotional distress. The change is so obvious that his friends
and acquaintances remark on it without being told what has
happened.
On the other hand, megadose folic acid has been quite helpful
in several of my depressed and a few of my schizophrenic
patients. I will never forget the young man who recovered
from a schizophrenic episode only after increasing folic
acid intake to 40 mg. He remained well for a year but relapsed
when he stopped the treatment. After that it required a
70 mg dose to defeat the illness.
Folic acid acts in concert with vitamin B12 in the production
of adenosyl-methionine, an amino acid with a powerful ability
to elevate mood and enhance mental acuity. One of the early
signs of folate deficiency is mood depression and, as I
said earlier, studies of hospitalized patients with depression
show a tendency to low folic acid levels. When depression
is accompanied by fatigue, treatment with folic acid is
particularly likely to work.
Wheat allergy or intolerance is a common cause of folate
deficiency. Gluten, the wheat protein, causes inflammation
of the intestine and mal-absorption of folic acid in sensitive
individuals. Infection with the parasite, Giardia lamblia,
can also inflame the bowel and interfere with folate absorption.
It is a good idea to check folic acid levels in anyone who
suffers from persistent intestinal symptoms, particularly
diarrhea or excessive gas and bloating. Since folate must
be digested by pancreatic juice in the duodenum, any malfunction
in that area is likely to interfere with this vitamin.
There are many other indications to consider folic acid
therapy. Neuropathy, nerve damage, is one of these, restless
legs another. Post-partum depression and confusional states
of the elderly are two additional psychiatric needs for
folic acid. Aplastic anemia, even if due to a poisoning
or drug reaction, may be responsive to folic acid. Recovery
from any acute illness or trauma is likely to benefit from
extra folic acid.
Folate deficiency is rare in breast fed infants but common
in infants fed cows milk and commercial formula. Due to
heat treatment, pasteurization, a milk protein that transports
folate into the blood stream is destroyed. Without this
protein, half the folic acid in food and supplements never
makes it into the tissues where it is required for optimal
cell function. Does this contribute to impaired growth and
impaired brain development? I really worry about that when
I know that the majority of American mothers do not nurse
their babies and that the level of intellectual ability,
as measured by scholastic test scores (SAT) has declined
over 10 percent in the past 20 years. I think it is more
likely that impaired brain development is behind this disaster
than any lack of ability or effort on the part of our teachers
and schools. When it comes to feeding children, Mother Nature
still seems to know best! Natural foods in their raw state
contain plenty of folic acid.
Richard A. Kunin, M.D. ©2000
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