OptiBoost 30 Capsules For immune system support Vitamins A and C are combined with zinc, bioflavanoids and natural herbal extracts of African potato, Sutherlandia and olive leaf extract for a more natural solution than medication to pack the punch. 5 things to avoid for a healthy immune system Refined carbohydrates, sugar and processed foods Smoking and excessive drinking Lack of sleep and exercise Exposure to chemicals, pollution, pesticides, insecticides Overuse of antibiotics and pain killers