Essential Principles of 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. Nevertheless, 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.