Immune system enhancers are the products which make Immune system strong and defensive against foreign particles which can be harmful to body. This  is approach to help deceased people to fight against diseases, also for healthy people to stay healthy. As "prevention is better than cure."

Immunity is very important for person to fight against infections. there are multiple drugs available in market for generating immunity. but the one which is naturally derive has a long term effect. Natural sources for immunity is through diet. Diet rich in antioxidants is good for immunity. Foods rich in Beta carotene, Vitamin C, Vitamin E, Zinc, Selenium etc are best sources to gain immunity through diet rather than having supplements. 

Foods such as guava plums, berries cherries, kiwi, melons, olives, green-leafy vegetables, tomatoes, carrots, beets, broccoli, mushrooms, fish, oysters, bone broths, garlic-cloves, ginger, cinnamon, mint, tulsi, curry-leaves, cardamom, green tea etc can be included in your diet to have perfect antioxidants in your diet to gain immunity.