Complement with elderberry and vitamins to strengthen defenses and stimulate the immune system. Elderberry helps the body's defenses, vitamin D and Zinc help the immune system function. Vitamins B2, B6 and B12 help reduce tiredness and fatigue. Vitamin C contributes to the normal functioning of the immune system. How to use: Take 10 ml a day. Shake before using. It can be diluted in water or other liquids.