Vitamin A
Vitamin A was given the first letter of the alphabet for
a name because it was the first vitamin to be discovered.
It was found that vitamin A has a large number of uses in
the body including keeping eyes healthy, aiding cell growth
and also helping boost the immune system. However, vitamin
A is not only absorbed directly but it is also created by
the body by converting beta carotene into vitamin A.
Vitamin A itself is found in a number of foods such as eggs,
milk, liver and meat. Beta carotene that the body can convert
into vitamin A is found in many fruits and vegetables, especially
the red, orange and green coloured ones. The most important
point to remember that consuming too much pure vitamin A can
be toxic. It is essential not to exceed the recommended daily
allowance for vitamin A. The actual recommended allowance
of vitamin A varies depending on a person’s age, sex
and other factors. While the actual amount of vitamin A consumed
may be toxic if the recommended daily allowance is exceeded,
there is a far higher limit to how much beta carotene can
be consumed. Therefore it is advisable to concentrate on obtaining
the greatest amount of beta carotene which the body can then
convert to vitamin A, rather than consuming vast quantities
of pure vitamin A rich foods.
Many people will remember being told that eating lots of
carrots helps you to see in the dark and that is down to the
vitamin A that is produced from the high levels of beta carotene
that are found in the vegetables. Other foods which have high
levels of beta carotene that can be converted to vitamin A
include tomatoes and dark green leafy vegetables, such as
spinach. Beta carotene is not only used to form vitamin A,
but it is also a powerful antioxidant in itself. None of the
beta carotene that is absorbed is wasted as any excess after
conversion to vitamin A has taken place is used to fight the
harmful free radicals within the body. Vitamin A also helps
fight infections and illnesses by helping tissues that line
various parts of the body, including the eyes, mouth, nose,
throat and lungs, to grow and also to repair them if they
are damaged to prevent infection. Children also need plenty
of vitamin A to help their bones and teeth to develop properly.
|
