Vitamins

Vitamins are essential for our body's chemical reactions. However, they are not usually manufactured by the body: they are supplied by the diet. A vitamin deficiency (avitaminosis) must be diagnosed by a doctor. In most cases, it is the result of a serious illness. If you eat normally, you don't need any extra vitamins, contrary to what the advertising would have you believe. And vitamins have no effect on mental tone or memory!

Hypervitaminosis (intoxication due to an excess of vitamins) can have extremely serious consequences. 

Groups B, C and A, D, E, K

Vitamins are classified into 2 groups: water-soluble vitamins (groups B and C) and fat-soluble vitamins (groups A, D, E and K). If you consume too many water-soluble vitamins, the excess are rapidly eliminated by the kidneys. Fat-soluble vitamins, on the other hand, are stored in fatty tissue and the liver. The daily intake accumulates there, waiting to be used up. The body thus has substantial reserves (for several months), but this accumulation entails a risk of overdosage, which can lead to serious illness. So it's best not to take vitamin supplements without the advice of a doctor, or at least a pharmacist. Especially as a balanced diet provides the body with everything it needs. If you do take a vitamin complex, avoid those overly concentrated in vitamins A, D, E and K. Finally, don't forget that the pleasure you derive from eating contributes just as much to your health and well-being !

Where can I find vitamins?

Trace elements play similar roles to vitamins. The big difference is that they are non-organic elements: zinc, iodine, iron, selenium, copper... The body needs them in very limited quantities.

Minerals -- calcium, phosphorus, magnesium, sodium, chlorine, potassium -- are required in larger quantities, but are amply supplied by the diet.

There's no need to absorb anything else.