Vitamins are substances that must be brought daily to our body, unable to produce them (except for vitamin D).
Active in minute quantities, they intervene during reactions that permanently transform matter and energy in the cells (“metabolic reactions”). Each has a specific biological role (see table water-soluble vitamins and table fat-soluble vitamins).
Thirteen vitamins have been identified to date.
Trace elements, like vitamins, are essential for the proper functioning of the body. They are trace minerals that also participate in the metabolism of cells.
In particular, they are involved in the reactions that transform food materials into living matter and waste products. Fifteen trace elements are considered essential for good health (see table trace elements).
Inputs: natural or complementary?
For the normal needs of the body, a varied and balanced diet is sufficient to provide the necessary quantities of vitamins and trace elements. Fresh vegetables and fruit should be eaten every day. The different vitamins are present in four food groups: cereals, meat and eggs, milk and its derivatives, fruit and vegetables.
Beware! Vitamins are fragile. Take the following precautions:
Prepare and cook vegetables quickly.
Fruits and vegetables must be kept cold.
Freezing preserves the vitamins in food.
If deficiencies are rarely observed, deficiencies (daily intakes slightly lower than recommended) may occur for both vitamins and trace elements (especially iron, zinc, copper and iodine).
The deficiencies do not lead to serious illnesses but to a general decline in form (fatigue, loss of appetite…) and a state of increased fragility in relation to external aggressions (stress, infections, illnesses…).
These situations of vitamin and/or trace element deficiency are not exceptional and are observed in all categories of the population. Moreover, it is essential to know that needs vary according to age, life circumstances and lifestyle.