Rotbäckchen Vital Immune Formula supports the normal function of the immune system in three ways with zinc, vitamin C and D3. Since the body cannot produce zinc itself, this vital trace element must be ingested in sufficient quantities through food. In the cold season, an additional supply of vitamin D can make sense to cover the need for this important immune-relevant vitamin. Rotbäckchen Vital Immune Formula does not contain any preservatives, colors, sweeteners or flavorings and is free of alcohol, gluten and lactose.