The word vitamin was coined by Casmir Funk in 1911 with regards to the thiamine, indicating that this compound was indispensable to life and its structure included an amino group. The term was then extended to all substances belonging to this category.

Vitamins constitute a heterogeneous set of organic compounds indispensable for growth, the integrity of cells and for the correct functioning of metabolic processes.

They have the following characteristics:
• they don’t have calories.
• they act in very low doses (less than 1 mg to 100 mg daily).
• are essential substances not synthesized by man (it’s essential to introduce them with food).
• Vitamins may be reproduced in the laboratory because the exact chemical compositions are known.
• The properties of the vitamins are inactivated by exposure to light, oxygen and high temperatures.