At this point there is no European mandatory regulation as to
how far the added amount of vitamins may exceed the declared
concentration on the label. There are recommended practices on
national bases like a position paper worked out by the German Food
Chemical Society (LChG) regarding recommendations concerning
the tolerance of nutrient declarations (LChG, 2009). For vitamins a
tolerance of ±30% for FA compared to the label declaration is generally
accepted. Due to instability of some vitamins an additional
dosage of up to 50% is considered necessary and may even be
exceeded in some cases, like the fortification of fruit juices.