Vitamins are organic
substances that are not produced
by the human body, but they
are required to sustain life.
Because the body cannot supply
these essential substances,
vitamins must be obtained through
of the body's need for vitamins
has been gained through scientific
studies that has related certain
diseases such as pellagra, rickets,
and scurvy with a lack of a
particular vitamin in the diet.
Further studies have found that
vitamins serve many functions
in the body and they are required
by nearly every organ in the
play an important role in aiding
metabolism, reducing fatigue,
increasing mental alertness,
and increasing the body's resistance
to bacterial infection. Without
the essential vitamins, the
body cannot function properly
and life cannot be sustained.
How much of a vitamin
does the body need?
Because every person
is unique, each will have his
or her own vitamin requirements.
Some factors influencing the
nutritional needs of each individual
are genetics and lifestyle.
Some people are better at absorbing
nutrients than others due to
genetics. Others require more
nutrients due to their particular
how much of a certain nutrient
the body needs cannot be universally
determined. However, recommended
dietary allowances (RDAs) have
been established by the Food
and Nutrition Board in the United
States. These allowances apply
to the level of dietary intake
of a particular nutrient that
satisfies the nutritional requirements
of a particular group of people.
have not been established for
all vitamins due to a lack of
information. However, adequate
intake (AI) levels have been
established. Tolerable Upper
Intake Levels (UL) have also
been determined to reduce the
risk of adverse effects arising
from too much nutrient intake.
most people, taking nutritional
supplements that satisfy the
RDA have no adverse effects.
However, too much vitamin intake
can have serious consequences
to the body's health. An overdose
of certain vitamins such as
vitamins A and D can have toxic
effects. Although controversial
studies on the benefits of taking
mega doses of vitamins have
been reported, excessive nutrient
intake is generally not recommended.
a person needs to supplement
his or her diet with nutritional
supplements is a controversial
topic. The only universally
accepted opinion about supplements
is that they are no replacement
for a healthy diet. Nor can
the body absorb the nutrients
contained within supplements
general, a person can prevent
nutrient deficiencies with a
balanced diet. However, this
fact does not imply that a person
can achieve optimum health from
just an adequate diet. In many
cases, people are unable to
satisfy their nutrient needs
with their daily diet. Simply,
people don't eat well.
supplements provide a means
of maintaining a healthy balance
of nutrients in the body. It
must be emphasized, however
that they are not a replacement
for a healthy, balanced diet;
they are as their name implies,
a complement to one's diet so
that an individual may maintain
a healthy nutritional balance.