Selenium
Selenium contains powerful antioxidants that help boost the immune system to fight infections. This mineral is best absorbed through animal foods, except for Brazil nuts, which offer more than 100 percent of the daily value in a single nut. Excellent sources of selenium include tuna, sardines, halibut, red meat, chicken, turkey, and cottage cheese.
The body only requires small amounts of this mineral, so you shouldn’t consume these foods in excess. Do not take more than one to two Brazil nuts per day to avoid overconsumption.