Grapefruit (Vitamin C)

Grapefruit is not only delicious but immune boosting too. It is rich in Vitamin C, which is known as an antioxidant that fights harmful free radicals. Vitamin C helps strengthen immune system by attacking the core (nuclei) of the virus. Vitamin C also plays a vital role in the connective tissues of your bones. The stronger your connective tissues, the more resistant they are from pathogens.