It is preferable to do analyzes before taking food supplements insofar as an analysis is the means of identifying possible deficits or deficiencies. After supplementation, it also makes it possible to check its effectiveness”, explains Professor Vasson, pharmacist-biologist. However, after a flu or a cold, general practitioners generally prescribe vitamin C or a course of multivitamins to help the body recover, without asking for analyzes beforehand. The food supplement based on vitamins most often provides nutritional doses close to those that can normally be found in food. It is therefore sufficient to consume them with common sense, at certain times of the year when the body is more stressed, or in periods when the diet is less balanced.