Selenium is a trace mineral that is essential for human health. It plays a critical role in metabolism and thyroid function and helps protect the body from oxidative damage and infection. Selenium is naturally present in many foods. Here are some natural food sources high in selenium:

1. Brazil Nuts: One of the richest sources of selenium, just one or two nuts can meet your daily requirement.
2. Seafood: Fish like tuna, halibut, and sardines are excellent sources of selenium. Shellfish such as oysters, mussels, and shrimp also contain high levels.
3. Meat: Beef, chicken, turkey, and pork are good sources of selenium, especially if they are fed selenium-rich diets.
4. Eggs: Contain moderate amounts of selenium.
5. Whole Grains and Seeds: Foods like sunflower seeds, brown rice, and whole wheat bread provide selenium.
6. Dairy Products: Milk and yogurt contain selenium, although in smaller amounts compared to other sources.
7. Fruits and Vegetables: While not as high in selenium, some like spinach, bananas, and mushrooms contribute to overall intake.

A varied diet typically provides sufficient selenium, but in some regions where soil selenium levels are low, supplementation may be necessary. Always consult with a healthcare provider before starting any supplement regimen.