If you’re looking to lose weight, you might have seen selenium pop up as your miracle weight loss mineral.

But in reality, just eating selenium-rich foods or taking a selenium supplement isn’t going to make you lose weight. It’s a little more complex.

Diet and exercise are two key components when it comes to weight loss, but sometimes an under-active thyroid (aka hypothyroidism) can make it difficult.

Your thyroid helps regulate your metabolism, which is basically how your body converts food into energy by burning calories.

According to the American Thyroid Association, those with hypothyroidism tend to have a low basal metabolic rate (BMR). With a low BMR, your metabolism is moving a little bit slower than normal, so you’re not burning calories as quickly and may notice some weight gain.

Since selenium is an important mineral for thyroid function, it might help keep your thyroid in check. This *might* prevent weight gain that comes with hypothyroidism and aid in weight loss.

In a small 2019 study participants with hypothyroidism took selenium supplements every day for 4 months. At the end of the study, normal thyroid function was restored in 22 out of 45 participants (almost 49 percent). Plus 83 percent of those folks maintained normal thyroid function 6 months after stopping the selenium supplementation.

Another 2018 study also found that the intake of dietary selenium helped treat peeps with hypothyroidism. But the study stated further research needs to be completed to confirm this relationship.

Noshing on selenium foods could be the first step in getting this essential mineral. Selenium naturally pops up in soil and water, so you’ll find it in tons of plant and animal foods.

A 2016 study of more than 3,200 people found those who ate less selenium-rich foods had a higher body mass index (BMI). Researchers also found that every 0.45 microgram per pound per day increase in dietary selenium resulted in a 3 to 6 percent decrease in body fat.

Chances are you’re getting enough selenium if you eat seafood, meats, and brazil nuts on the reg. But, the selenium content in plant-based foods can vary depending on the soil. So the location food is grown can either increase or decrease its total selenium.

Foods that typically contain high amounts of selenium include:

FoodMcg (micrograms) per servingPercent Daily Value (DV)
Brazil nuts544 per 1 ounce (6–8 nuts)989%
yellowfin tuna92 per 3 ounces cooked167%
halibut47 per 3 ounces cooked85%
sardines45 per 3 ounces82%
ham42 per 3 ounces76%
shrimp40 per 3 ounces73%
enriched macaroni37 per 1 cup cooked67%
cottage cheese (1% milkfat)20 per 1 cup36%
brown, long-grain rice19 per 1 cup cooked35%
hard-boiled egg15 per 1 large egg27%
whole wheat bread13 per 1 slice24%

Most folks get plenty of selenium from foods. But if meat, seafood, and brazil nuts aren’t your jam, you can also take a selenium supplement. Just get the A-OK from your doc and make sure you’re not double-dipping because selenium may already be in your daily multivitamin.

When it comes to weight loss, selenium supplements may be helpful even if your thyroid function is normal. A small 2020 study with 37 overweight adults found that those who were following a calorie-restricted diet and taking a 240-microgram selenium supplement lost more weight than those only following the diet.

The same study also found that the supplement group had lost more fat and had lower levels of leptin, a hormone that regulates fat storage.

The recommended Daily Value (DV) for selenium is 55 micrograms for adults. But according to the National Institute of Health, folks 14 and up can take up to 400 micrograms of selenium.

Many selenium supplements come in 200-microgram tablets taken once per day which is over the recommended intake, but not near the upper limit. Your body may not even absorb the full 200 micrograms either, depending on the type of selenium used. The body absorbs more than 90 percent of a selenium supplement containing selenomethionine, but only 50 percent of selenium from selenite.

When it comes to food, avoid eating handfuls of brazil nuts on a daily basis. Although they contain healthy fats and other nutrients, a 1 ounce serving (6 to 8 nuts) pushes you way beyond that upper limit and could wind up being more harmful than helpful.

Consistent selenium intake over that 400-microgram upper limit can be toxic and may cause side effects like:

Severe issues can also arise including difficulty breathing, tremors, kidney failure, and heart failure.

Before popping a daily supp, try and meet your needs through food. Here are some vegetarian and nonvegetarian meal options to add selenium to your morning, afternoon, and evening.

BreakfastLunchDinner
2 hard-boiled eggs and 1 cup of 1% milk (38 mcg)Chicken salad sandwich with 3 ounces of chicken and slices whole wheat bread (48 mcg)Shrimp pasta with 3 ounces shrimp, 1 cup macaroni, and 1 cup marinara (81 mcg)
1 cup of oatmeal (made w/ water) topped with 1 chopped up brazil nut (111 mcg)Lentil soup with at least 1 cup of lentils and 1/2 cup of spinach (11 mcg)Beans and rice with 1 cup of baked beans and 1 cup brown rice (33 mcg)

Adding selenium-rich foods or a selenium supplement could be especially helpful if you have a low functioning thyroid system and deal with hypothyroidism weight gain.

So selenium may be beneficial if you’re trying to lose weight, but it’s not the only way. You can’t just pop some selenium and skip the whole diet and exercise part of a weight loss journey. Healthy weight loss takes time.

Just like with any vitamin or mineral, it’s always important to have a conversation with your doctor before adding a supplement to make sure it’s safe and you’re not taking in too much.