A vitamin is a
small molecule that your body needs to carry out a certain
reaction. Your body has no way to create vitamin molecules itself,
so the vitamin molecules must come in through food that you eat.
For example, Vitamin A is has the formula C20H30O.
Vitamin B1 (thiamin) has the formula C12H16
N4OS. Vitamin C has the formula C6 H8
O6, and so on. The human body is known to need at least
13 different vitamins:
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Vitamin A
(Fat soluble, Retinol) Comes from Beta-Carotene
in plants (When you eat
Beta-Carotene an enzyme in the stomach turns it into Vitamin
A). |
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Vitamin B
(Water Soluble, several specific vitamins in the
complex)
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| Vitamin C
(Water Soluble, Ascorbic Acid) |
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| Vitamin D
(Fat Soluble, calciferol) |
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| Vitamin E
(Fat soluble, tocopherol) |
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| Vitamin K
(Fat Soluble, Menaquinone) |
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| Pantothenic
Acid (Water soluble) |
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| Biotin (Water
soluble) |
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Inside the body,
vitamins are used in many unique ways. For example, one of vitamin
A's main roles is in the production of retinal. Retinal is
used within the rods and cones in your eyes to sense light. There
is no way for your body to produce retinal without vitamin A, and
without retinal you cannot see.
As another example,
the different B vitamins are often embedded within the structure
of different enzymes that a cell produces. For example, aspartate
aminotransferase is an enzyme that transfers amines between amino
acids. Each copy of the enzyme contains two vitamin B6 molecules,
and without these molecules the enzyme cannot do anything.
One use of Vitamin
C is in the formation of collagen. Collagen is produced by special
ribosomes in certain cells, and then exported out of the cells to
form collagen networks. During the process of collagen formation
the body must manufacture hydroxylproline from the amino acid
proline. Vitamin C is essential to this reaction. Without vitamin
C collagen cannot be produced, and the first signs are very weak
(and easily broken) blood vessels and loose teeth (which are held
in their sockets by collagen).
The body is able to
store some vitamins, like vitamin A (up to a year's supply is
stored in your liver). Other vitamins need to be re-supplied
frequently.
