Vitamins

 Vitamins

Introduction

The disease Scurry is said to have afflicted the Crusaders. During 1400's and 1500s it was one of the prevalent diseases in Europe. Scurvy was reported by Vasco de Gama during his sea voyages, and Jacques Cartier in 1535 reports loss of 25% of his sailing crew due to scurvy. As early as 1601 ships of the East India Company carried oranges and lemons to prevent scurvy on the recommendation of the English privateer, Sir James Lancaster.

In 1720 Kramer, an Austrian army physician had written about the disease scurvy and its cure after the intake of oranges or green vegetables. In 1753 Captain Lind of the British Navy proved that Scurvy could be cured by oranges and lemons.

In 1882 Admiral Takaki, Director-General of the Medical Service in Japan, observed that Beriberi could be cured by increasing fresh vegetables, meat, fish and other proteins in the diet. In 1890 Eijkman in Dutch East Indies found out that birds fed with polished rice developed Polyneuritis along with other signs similar to that of Beriberi.

Dr. Casimir Funk of the Lister Institute of London isolated the anti beriberi substance in pure form and as it was thought to be an amine, and at the suggestion of Dr. Max Nierenstein the term vitamine was used.

In 1888 Lunin and Professor Bunge of Basle observed that life was not sustained by diet containing purified proteins, carbohydrates, fats and minerals, but when such food was supplemented by milk the normal growth and longevity are maintained. So they concluded that there must be some substances, besides carbohydrate, protein, fat and minerals, which are essential for life.

In 1915 McCollum and Davis established the presence of essential factors for growth in milk and egg-yolk.

·        Fat-soluble A found in eggs and butter

·        Water soluble B in milk, etc

In 1920 Professor J. C. Drummond suggested the term for this essential factor (vital) as vitamin.

Definition

        Vitamins are potent organic compounds which are found in foods in variable and minute quantity, and must be supplied to all organisms from external sources, so that specific physiological functions, vital to life, may go on normally. They are neither oxidized to supply energy nor used to build tissue structures.

General Characteristics

The general characteristics of the vitamins are given below:

1. Distribution. The vitamins are widely distributed in nature both in the animal and vegetable kingdoms. All vitamins are manufactured in plants. The animals can manufacture a few only but can store all up to some extent. Almost all common articles of food contain more than one vitamin.

2. Daily requirement. Vitamins can perform their work in very low concentration. Hence, the total daily requirement is usually very small. The daily need of any vitamin for any individual is not a fixed quantity. It varies according to the rate of metabolism. In all cases where metabolism requirement is very high, the vitamin requirement is proportionally more.

3. Store. Vitamins can be stored in the body to some extent, for example, the fat-soluble vitamins are stored in the liver and the subcutaneous tissue, vitamin C in adrenal cortex, etc.

4. Fate. Vitamins are partly destroyed and are partly excreted.

5. Synthesis in the body. Some vitamins are synthesized in the body; vitamin B complex is synthesized by micro-organisms in the intestinal tract.

6. Digestion-Vitamins are not destroyed in the digestive process and are, therefore, absorbed as such. Hence, all vitamins are effective when administered orally.

7. Mode of action. This is not exactly known in all cases. Several of them have been proved to act as a coenzyme of other metabolic enzymes. Since the enzyme system of a tissue is specific in nature, a particular vitamin acts selectively upon one tissue i.e., acts as a coenzyme of the specific enzymes of these tissues.

8. Essential constituent of diet. Although they are essential for life, yet all vitamins are not required for all the species of animals. The physiological requirement is met with the synthesis of a particular vitamin in the organism.

9. Non-antigenic. Vitamins are not antigenic.

10. Solubility. Some of them are soluble in water and others in fats and fat-solvents.

11. Artificial synthesis. Most of the vitamins have been artificially synthesized.