Vitamin A (Beta Carotene) This vitamin assists with the health of your intestines and respiratory system. Vitamin A-rich foods include carrots, sweet potato, spinach, broccoli and red bell peppers. Vitamin E This nutrient promotes the neutralization of free radicals by working as an antioxidant. Foods full of vitamin E include vegetable oils, nuts, seeds and avocado. Zinc There are many zinc-dependent enzymes in our body and deficiency has been linked with immune dysfunction. Zinc-rich foods include beans, seeds, nuts, meat, poultry and seafood. Protein Specific amino acids found in protein are essential for T-cell function, which are cells that protect the body against pathogens. Meats, poultry, seafood, eggs, beans, nuts and seeds all have lots of protein. These nutrients have been shown to help your immune system work most efficiently and effectively, but too much of a good thing can be harmful. Eat these nutrients in moderation and don’t go overboard. If you eat too many carro...