A vitamin is an organic substance that is essential, at very low doses, for the body.
Vitamins are substances required for our health that play an important role in nutrient uptake and utilisation. As the body is unable to produce these substances on its own (with the exception of vitamin D, vitamins B2 and B3, and vitamin K), vitamin intake is strictly dependent on dietary sources. Vitamins are essentially of plant origin (B-complex group vitamins) and are thus more particularly found in fruits and vegetables.
A vitamin has no energy value, for instance it does not release calories. It is nonetheless needed by the body to ensure normal overall function.
Vitamins help maintain a healthy balance as they enable cells to utilise nutrients, which are sources of energy.
Each vitamin has specific functions and cannot be used to substitute any other vitamin. In the body, many reactions require the presence of multiple vitamins and a deficiency in any one of these may impede the function of the others.
Vitamins are categorised into two families: