How to strong Immune system .Don't Smoke .Eat a diet high in fruits and vegetables .Exercise Regularly .Drink plenty of water Also there Vitamins that are Best for Boosting Immunity. .vit C ( ascorbic acid) .vit E ( tocopherol) .vit B12 ( mecobalamine) 1.Vitamin C / is one of the biggest immunity system Boosters of all. in fact. a lack of vitamin C can even make you more prone to getting sick. ( Sources of Vitamin C ) Fruits & Vegetables 1. Citrus fruits such as / lemon, Oranges, others are / kiwifruit, Strawbberis, Grapefruit, guava, Watermelon, Mango. 2. Vegetables such as / spinach, cabbage, turnip greens, other leafy greens, tomatoes, tomato juice. 2.Vitamin E / is a powerful antioxidant that helps the body fight off infection. ( Sources of Vitamin E ) Fruits & Vegetables Such as / Vegetables Oils, Nuts, Seeds, green leafy vegetables. 3.Vitamin B12 / vit B12 is a powerhouse. it helps make DNA nerve and blood cells. and a crucial for a healthy brain and immunity system. ( Sources of Vitamin B12 ) Fruits & Vegetables Such as / fish, chicken, meat, poultry, eggs, Beef liver, Animals products, such as, Milk, yogurt, cheese, ETC Dr. Hurmat sharifzai