Selenium deficiency refers to not having enough selenium in your system. Symptoms may include fatigue, muscle weakness, and infertility, among others.
Selenium is an important mineral. It’s
- thyroid hormone metabolism
- DNA synthesis
- protection from infection
The amount of selenium in food sources is largely determined by the quality of the soil used to grow them. Rainfall, evaporation, and pH levels all affect selenium concentration in soil. This makes selenium deficiency more common in certain parts of the world.
In the United States, selenium deficiency is thought to be rare. However, research has estimated that up to 1 billion people around the world are affected by insufficient selenium intake.
That same review predicts that the effects of climate change will gradually decrease soil selenium concentrations in many parts of the world, including the Southwestern United States.
Selenium is a particularly important mineral because it supports the function of several systems. These include the endocrine, immune, and cardiovascular systems. The thyroid, part of the endocrine system, is the organ with the highest concentration of selenium per weight of organ tissue.
According to a study published in 2020, selenium deficiency might also influence cognitive functioning. However, some research has shown
Selenium deficiency can produce a range of symptoms. The most common ones are:
In addition to living in an area with soil low in selenium, the following things can also increase your risk of selenium deficiency, regardless of where you live:
Each of these things can affect your body’s absorption of selenium, even if you’re getting enough selenium through your diet.
Who is adequate selenium especially important for?
Adequate selenium is especially important for some groups, such as people who:
Selenium deficiency tends to be found more often in communities than in isolated individuals. When selenium deficiency is suspected in a community, it is common to test for selenium in the nails or in scalp hair. It can also be diagnosed by blood tests.
In some cases, your doctor can measure your levels of glutathione peroxidase. This is an enzyme that requires selenium to function. If your level is low, you may not have enough selenium.
The first-line treatment for selenium deficiency is to try to eat more foods that are high in selenium.
- Brazil nuts (544 mcg per oz or 6 to 8 nuts, or 989% of the DV)
- yellowfin tuna (92 mcg per 3 oz. serving, or 167% of the DV)
- canned sardines, bones included (45 mcg per 3 oz serving, or 82% of the DV)
- beef steak (33 mcg per 3 oz serving, or 60% of the DV)
- beef liver (28 mcg per 3 oz, serving, or 51% of the DV)
- brown rice, cooked (19 mcg per cup, or 35% of the DV)
- baked beans (13 mcg per cup or 24% of the DV)
- whole wheat bread (13 mcg per slice or 24% of the DV)
Take care not to exceed the tolerable intake level of 400 mcg of selenium. Signs of too much selenium include a garlic-like odor on your breath and a metallic taste in your mouth.
When foods high in selenium aren’t an option, selenium supplements can also help. Many multivitamins contain selenium, but you can also find it as a standalone product.
Selenium supplements usually come in the form of either selenomethionine or selenite. Selenomethionine tends to be easier for your body to absorb, so it may be a better option for more severe deficiency cases.
The Food and Drug Administration does not monitor the purity or quality of supplements like they do for drugs. Talk with a qualified healthcare professional before you begin taking a selenium supplement.
Although selenium deficiency is rare, it’s important to make sure you’re getting enough of it and absorbing it properly. If you think you may have a selenium deficiency, work with a qualified healthcare professional to rule out other possible causes of your symptoms.