Chemistry Vitamins
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Topics Covered :

● Vitamins
● Classification of Vitamins

Vitamins :

`=>` It has been observed that certain organic compounds are required in small amounts in our diet but their deficiency causes specific diseases. These compounds are called vitamins.

`=>` Most of the vitamins cannot be synthesised in our body but plants can synthesise almost all of them, so they are considered as essential food factors.

`=>` However, the bacteria of the gut can produce some of the vitamins required by us.

`=>` All the vitamins are generally available in our diet.

`=>` Different vitamins belong to various chemical classes and it is difficult to define them on the basis of structure.

`=>` They are generally regarded as organic compounds required in the diet in small amounts to perform specific biological functions for normal maintenance of optimum growth and health of the organism.

`=>` Vitamins are designated by alphabets `color{red}(A, B,C, D)`, etc.

● Some of them are further named as sub-groups e.g. `color{red}(B_1, B_2, B_6, B_(12))`, etc.

`=>` Excess of vitamins is also harmful and vitamin pills should not be taken without the advice of doctor.

`=>` The term “Vitamine” was coined from the word vital + amine since the earlier identified compounds had amino groups.

● Later work showed that most of them did not contain amino groups, so the letter ‘e’ was dropped and the term vitamin is used these days.

Classification of Vitamins :

Vitamins are classified into two groups depending upon their solubility in water or fat.

(i) `color{green}("Fat Soluble Vitamins ")` : Vitamins which are soluble in fat and oils but insoluble in water are kept in this group.

● These are vitamins `color{red}(A, D, E)` and `color{red}(K)`. They are stored in liver and adipose (fat storing) tissues.

(ii) `color{green}("Water Soluble Vitamins ")` : `color{red}(B)` group vitamins and vitamin `color{red}(C)` are soluble in water so they are grouped together.

● Water soluble vitamins must be supplied regularly in diet because they are readily excreted in urine and cannot be stored (except vitamin `color{red}(B_(12))`) in our body.

`=>` Some important vitamins, their sources and diseases caused by their deficiency are listed in Table 14.3.