Yes, there are foods that contain certain vitamins and minerals that are thought to help potentially prevent the flu. Some of the foods or beverages you can eat to help prevent the flu include: Vitamin D foods, such as mushrooms, fortified milk, and salmon Iron-rich foods, such as nuts, white beans Zinc-rich foods, such as oysters, red meat, and poultry Selenium-rich foods, such as brown rice, oatmeal, cashew, yogurt