Selenium is a trace mineral naturally found in seafood, nuts, meat, dairy and grains, as well as in supplements. Selenium is essential for DNA, thyroid hormones, reproduction and oxidation protection. It may also protect against cancer and reduce the risk of cardiovascular disease. The recommended dietary allowance of selenium for adults ages 19 to 50 years old is 55 micrograms per day.
Grains and Vegetables
The selenium content in plant-based foods can vary depending on the soil in the location where the crop is grown. In general, one slice of whole-wheat bread, 1 cup of oatmeal and 1 cup of baked beans each contains 13 micrograms of selenium. A cup of enriched pasta contains 37 micrograms, and a cup of cooked brown rice contains 19 micrograms. Vegetables tend to be relatively poor sources of selenium. One cup of frozen spinach contains 11 micrograms, compared to a cup of iceberg lettuce, which doesn't contain any. Carrots also do not contain any selenium. A potato contains only 1 microgram.
Meat and Poultry
Meat is a good source of selenium that Americans rely on for the mineral. Three ounces of turkey contains 31 micrograms of selenium, while 3 ounces of chicken contains 22 micrograms. Three ounces of beef steak and ham contain 33 micrograms and 42 micrograms, respectively. Three ounces of 25-percent-fat ground beef contains only 18 micrograms of selenium. Organ meats contain a higher amount of selenium than muscle meats.
Brazil nuts are one of the best sources of selenium, depending on the soil content. Brazil nuts can contain up to 544 micrograms of selenium for only 1 ounce. An ounce of sunflower kernels has 23 micrograms, compared to an ounce of almonds, which has less than 1 microgram. An ounce of cashews, pistachios and walnuts has 6, 3 and 2 micrograms, respectively.
Seafood and Dairy
Seafood and dairy are other good sources of selenium. Three ounces of tuna has 92 micrograms of selenium, halibut has 47 micrograms, sardines have 45 micrograms and shrimp contains 40 micrograms of selenium. One cup of 1 percent cottage cheese has 20 micrograms of selenium. A cup of 1 percent milk and a cup of low-fat yogurt each contains only 8 micrograms of selenium.