Nutritional Deficiencies in Adults
The effects of nutritional deficiency
can be experienced anywhere on a scale from overt deficiency
diseases like scurvy or pellagra, to mild under-functioning
of the immune, hormonal, nervous or other systems.
Commonly used blood tests may fail to
identify a problem since the blood is subject to what is known
as "homoeostatic control," that is to say blood
nutrient levels are always more or less constant. Excessive
variations could be dangerous. Here's an illustration using
calcium as an example.
If blood calcium levels are getting low,
the body could develop a dangerous condition known as "tetany,"
leading to convulsions. So the blood borrows calcium from
the bones, hoping to put it back later. If the calcium shortage
continues, more and more calcium will be "borrowed"
from the bones. The blood will continue to show normal calcium
readings, but the bones will become demineralized and osteoporotic.
The same applies to most nutrients, and
organs or structures other than the bones may be involved.
As Adelle Davis, a nutritionist writing in the 1960s, remarked:
- "The first stage of a
dietary deficiency occurs when there is failure of supply
— either because food is mishandled, the diet is poorly
selected, or the individual, for one of many reasons (...)
has increased his needs. Failure of supply may also be initiated
or aggravated by difficulties in the digestion, the absorption,
or transport of nutrients within the body. Other difficulties
may be created by a breakdown in enzyme systems.
- "Once supply has failed
for any of these reasons, there will be a drop in the blood
levels of the nutrient. The blood now draws upon the tissues
and when that process comes to an end, it borrows from the
organ reserves. Note: Although you are well on your way
towards trouble at this point, the blood levels of nutrients
reveal nothing abnormal, because of the borrowing the body
initiates to achieve more equitable distribution of an inadequate
supply.
- "Then functional disability
begins — indigestion, nervousness, irritability, a tendency
to weep without provocation, a shortening of the memory
and attention spans, difficulty in concentration, insomnia,
and bad dreams — for which the doctor's X-ray, blood tests,
urine analysis, stethoscope and blood-pressure instruments
will find no physical justification (...)."
- — From "Eating
Right for You," Adelle Davis 1967.
Only if tissue and organ reserves become
so depleted that the deficiency begins to show up in the blood,
will a condition such as "scurvy" or "beri-beri"
be diagnosed. About 30 people a year in Britain die from these
diseases, according to a 1991 government survey.
Meanwhile, in people who never reach this
drastic endpoint because their deficiency is not absolute,
what damage is occurring to their ability to make hormones,
corpuscles, enzymes and other substances needed for good health?
Drained of the raw materials they need to make these substances,
how can the organs function efficiently? Organ biopsies (small
samples of tissue) would show a deficiency state more clearly
than a blood sample, but would be extremely impractical.
While the initial symptoms of sub-clinical
nutritional deficiency may be minor, such as fatigue,
weakness, poor
skin condition, lowered
immunity, mood changes
and other symptoms mentioned above, damage
and disturbance to metabolic functions as a result of the
deficiency are potentially very serious.
For instance, a lack of folic acid can
cause birth defects in unborn children, or can encourage
cholesterol deposits to form in arteries. A lack of
antioxidant nutrients or those needed to metabolize magnesium,
methionine or molybdenum may result in an increased level
of highly toxic intermediates, such as acetaldehyde, which
are produced by the liver in the course of its detoxification
functions.
The accumulation of such substances has
been linked with the development of diseases such as Parkinson's
and motor neurone disease. But because such diseases
take many years to develop, no connection with nutritional
deficiencies is suspected by conventional medical practitioners.
An inadequate zinc intake can lead to
a decreased production of stomach acid and digestive enzymes,
and thus worsening nutritional deficiencies due to impaired
digestion and absorption. Zinc and other nutrients are
needed for countless tasks such as tissue repair, hormone
and enzyme production, and immunity.
A very considerable body of scientific
literature exists describing beneficial results of studies
giving dietary supplements to individuals with a variety of
clinical illnesses. Surprisingly, it is sometimes assumed
that these positive results have nothing to do with the correction
of nutritional deficiency. In fact, the nutritional status
of the test subjects is sometimes not measured in advance
of the studies to ascertain whether there is any difference
in results between those with a low or a normal status of
the nutrient in question.
It is generally recognized that certain
groups are especially vulnerable to develop nutritional deficiencies:
pregnant or lactating women, those on weight loss diets, children
and adolescents, and the elderly.
Causes of Nutritional Deficiency
Causes of Inadequate Intake
These include poverty,
starvation, famine, poor food selection, bad cooking methods,
weight-loss diets, ignorance, food fads (particularly in children),
dental problems (leading to the selection only of foods which are
easy to chew), apathy (particularly in the elderly), anorexia, and a
reduced sense of taste.
Deficiencies of a number of nutrients such as zinc and B vitamins
may lead to anorexia. Zinc deficiency in particular can result in a
reduced sense of taste which leads to faddy eating as sufferers
unconsciously learn to select only foods with a strong taste such as
highly salted or sweetened foods and strong cheese.
Causes of Inadequate Digestion
These include poor chewing, and a reduced production of gastric
acid, bile and pancreatic and gut enzymes. These secretions are in
turn dependent on the availability of a number of nutrients such as
zinc, amino acids and B vitamins. However protein cannot be broken
down to amino acids, nor vitamins and minerals extracted from food
without sufficient gastric acid and digestive enzymes.
Causes of Inadequate Absorption
Nutrients are absorbed through the villi and microvilli located
on the walls of the small intestine. Absorption mechanisms may be
complex — dependent on carrier molecules which transport the
nutrients through the epithelium into the bloodstream on the other
side. Other nutrients diffuse through the epithelium.
Nutrients which have not been digested into sufficiently small
particles cannot be absorbed through the gut wall. Likewise, any
inflammation of the gut wall, such as that caused by food allergy,
dysbiosis (excess of harmful gut bacteria) or other sources of
irritation, and also increased gut permeability, may cause the gut
wall to become dysfunctional and compromise its absorption ability.
Chronic diarrhea also causes malabsorption, since intestine
contents pass through too quickly for proper absorption. Parasitic
infestations (e.g., worms) can result in severe malabsorption. In
particular, tape-worm utilizes vitamin B12, making it unavailable
for absorption. Tea, coffee and phytic acid (found in bran) can bind
minerals such as zinc and iron in the intestine, making them
unavailable for absorption.
Causes of Inadequate Cellular
Assimilation
Once nutrients enter the bloodstream, they have to be taken up by
the cellular systems which use them. One of the principal problems
that can occur with this process is that some toxins commonly
present in the body appear to be very similar to essential
nutrients.
For instance, the chemistry of lead resembles calcium so greatly
that if calcium is in short supply and there is plenty of lead
available, then lead can be absorbed instead of calcium both from
the gastrointestinal tract (if ingested) and from the bloodstream
into cellular systems.
The problem is that lead cannot perform the same tasks as
calcium, so it disrupts the function of the systems that are
attempting to use it, and these effectively become
calcium-deficient. Countless other toxins can have similar
disruptive effects on metabolism and function. Consequently, they
need not be present in large quantities to have these effects.
It is also possible that the mechanisms, which pump specific
nutrients from the blood into the cells, can become damaged by
toxins, nutritional deficiencies, or even viruses or other
micro-organisms. Symptoms may occur, suggesting that these nutrients
are deficient even when large amounts are present in blood.
With ME (myalgic encephalomyelitis) or chronic fatigue syndrome,
for example, muscle pain is thought to be due to chronic muscular
spasm, a common symptom of
magnesium deficiency. Supplementation appears to make little
difference to sufferers in the short term, but magnesium injections,
which flood the cell with very large amounts of magnesium, appear to
offer temporary relief. It is thought that in these cases some
damage may have occurred to magnesium uptake mechanisms, perhaps by
unknown toxins.
The contraceptive pill is one of the many medications that
disrupts normal nutrient status in the blood and cells, and results
in increased requirements. Nutrients most often affected include
vitamin B6, folic acid, vitamins C and E, and zinc. When deficiency
symptoms seem to occur in the absence of any dietary inadequacy,
this is also known as a "functional" deficiency.
Causes of Increased Needs
The ordinary rules of genetic diversity dictate that some
individuals will have higher requirements for certain nutrients than
others. Also, smoking, certain medications, heavy exercise, stress,
alcohol, pregnancy, breastfeeding, infections and rapid growth are
all factors that increase our nutritional requirements.
Experience with the nutritional treatment of many individuals
suffering from mental illness suggests that a prolonged nutritional
deficiency state can lead to exceptionally raised baseline
requirements for certain nutrients, particularly vitamins B3, B6 and
zinc. These exceptionally raised requirements have been termed
"vitamin dependency" states. Many individuals are not free of
symptoms such as hallucinations and severe depression
— unless these dependency states are acknowledged and appropriately
treated.
For instance, doctors treating pellagra victims in the 1930s
observed that some sufferers could only remain symptom-free by
constantly taking 600mg a day of vitamin B3. It is interesting to
note that this is fifty times the amount needed to prevent the
disease in those who have never had it.
As reported by psychiatrist Dr. Abram Hoffer, the treatment of
many veterans who suffered arthritis and residual psychiatric
symptoms after being detained for lengthy periods in Japanese
prisoner-of-war camps in World War II was not fully successful until
they were given 1 or more grams a day of vitamin B3.
Causes of Increased Losses
Such causes include, among others, menstruation, heavy prolonged
physical work or exercise, diarrhea, use of diuretics, and hot
climates causing heavy sweating.
Laboratory Tests for Nutritional
Deficiencies
The measurement of blood levels of
nutrients, although widely used in conventional medicine, is not
usually sensitive enough to detect sub-clinical deficiencies. Other
methods may be more appropriate, depending on the nutrient. Such
methods may be "functional" tests.
In other words, instead of measuring the
nutrient itself, the investigator measures levels of a metabolite (a
product of metabolism), which is dependent on the nutrient for its
production, before and after supplementation with the nutrient. Low
metabolite levels before supplementation, followed by significant
increases afterwards, can indicate a low "activity" of the nutrient,
and therefore a functional deficiency.
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