|
What is a Vitamin?
Vitamins are substances that must be obtained from dietary sources
because they cannot be produced endogenously in sufficient
amounts to support basic physiological functions essential
for life. The term "vitamin" is derived from the Latin word
for life"vita", and "amine" because these substances were
initially believed to consist of amino groups. Vitamins are
organic compounds of carbon, oxygen, and hydrogen, and also
other functional groups containing nitrogen, phosphorus, sulfur
or cobalt. Vitamins are considered micro nutrients because
they are required in relatively small amounts (micrograms
or milligrams) when compared to protein, carbohydrate, and
fat.
Vitamins: Key characteristics
1. Organic compounds that differ from protein, carbohydrates, and fat because they cannot be oxidized to energy.
2. Needs are satisfied by intakes in microgram or milligram amounts.
3. Cannot be endogenously produced, or produced in amounts sufficient to meet needs.
4. Differ in availability depending upon the dietary source.
5. Inadequate intake, impaired absorption, and increased metabolic demand are the most common causes of deficiencies.
Types of vitamins:
|
