The egg is an encapsulated reserve of proteins, lipids, minerals and vitamins, which is remarkable for the diversity of nutrients, their high digestibility or availability and also for the balance between the various essential constituents. The avian egg has an incomparable nutritional value, not only for birds but also for humans. It can be defined as a low calorie source of ideal protein for humans covering (/100 g egg) 20 to 30% of man's daily requirements for a majority of minerals and vitamins, with the exception of vitamin C and calcium since the chicken embryo can use the egg-shell as a nutritional reservoir. The hen's egg as a nutrient is therefore appropriate for the majority of the population. Eggs are easily digested and absorbed, provide several essential nutrients and are therefore valuable in diets for infants, convalescent or elderly patients who may have greater difficulty digesting and absorbing nutrients. Moreover the egg is the only animal food that can be stored uncooked at room temperature for a noteworthy period.