Eggs
Eggs are a great source of vitamin D which boosts your immune system and the best part is that they are easy to add into your diet. They are chock full of protein, and protein is critical to the formation of bacteria and virus fighting antibodies, says Wesley Delbridge, R.D., a spokesperson for the Academy of Nutrition & Dietetics.
Citrus fruits
These fruits are full of antioxidants and vitamin C which protects you from infection by maximizing antibodies and boosting your immune system. Studies suggest that vitamin C can shorten the duration of colds. Also, citrus fruits are loaded with fiber, so you will feel fuller longer.