Selenium content in soil varies widely. The concentration of selenium in soil varies by region, so the amounts you're getting in your food will vary depending on where it was grown or where the animals were raised. Studies have shown that people living in areas with a low selenium content in the soil have three times of rate of heart disease than average. People who live in areas where the soil has high levels, on the other hand, have the lowest rates of heart disease. This correlation holds up anywhere in the world that it has been studied, which led scientists to look for an explanation.
There are some good dietary sources of selenium: egg yolks, seafood, poultry, beef and whole grains contain the highest amounts. Vegetarians don't have many decent choices — garlic, onions, mushrooms and seeds have modest amounts.
Brazil nuts are the most concentrated food source of selenium, featuring about 70-110 micrograms per nut. You could get your daily requirement of selenium by eating a 2 or 3 Brazil nuts every day.
The richest food sources of selenium are listed below. Use the numbers only to compare relative values, since actual selenium content varies widely from sample to sample.
To guarantee that you're getting sufficient amounts in your diet, eating Brazil nuts, or using a 200mcg. supplement daily, is your best bet. Many good multivitamins have this amount of selenium in them. This trace mineral, although needed in very small amounts, is too important to miss out on.
For more information on supplementing with selenium,
go to my page on Selenium Supplements