Vitamins and minerals keep your body running on all cylinders, including the lesser known mineral selenium. So if something feels off, it probably is — and it *might* be because you’re not getting enough of something!

What is a selenium deficiency?

A selenium deficiency means your body isn’t getting enough of this essential mineral.

Your body only needs a smidgen of selenium each day, but it supports your health in some big ways:

Selenium deficiency is rare, but not impossible. Here’s how to spot and fix low levels.

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Your body is pretty great at telling you when something’s off. The trouble is figuring out which vitamin or mineral needs a top-up.

These are the symptoms of low selenium (just remember, they could also indicate other deficiencies!):

Well, selenium *is* an essential mineral. Low levels = higher chance of feeling icky and developing certain illnesses.

Selenium might also help prevent four major health issues:

  • Cancer. Some health experts say selenium’s antioxidant count and immune system influence mean that it helps prevent cancer. But a review of 83 studies suggested that selenium levels don’t affect cancer growth at all.
  • Heart disease. Initial research suggests that consuming selenium along with a mix of antioxidants can reduce your risk of heart disease. The researchers found that supplementing antioxidants without selenium *or* with selenium alone didn’t have the same effect.
  • Age-related cognitive decline. Some experts suggest that healthy levels of selenium could reduce your risk of memory probs. Unfortunately, the research is mixed. One recent study found no link between selenium and dementia.
  • Thyroid disease. Selenium is important for healthy thyroid function. Research indicates supplementation is often recommended for folks with thyroid disease, but that doesn’t mean it should be taken preventatively.

Since a selenium deficiency can lead to infertility, it’s also an important player in healthy reproductive functioning. But, more research is needed to know exactly why and how selenium influences your ability to get preggo.

How much selenium do you need every day?

Teens and adults need 55 micrograms of selenium per day.

People who are pregnant or breastfeeding should aim for 70 micrograms daily.

Selenium deficiency is rare because most folks get 100+ micrograms per day from food or multivitamins.

If you eat a lot of selenium-rich foods, you might even be creeping toward the upper intake level (UL) — aka the highest healthy amount — which is 400 micrograms per day.

Good news! It’s usually pretty easy to get your levels back into the safe zone. Your best bet? Selenium-rich foods. The next step? Supplements.

Food sources of selenium

Let food be thy medicine! A typical serving of these selenium-rich foods offers *at least* half your recommended daily value (DV):

And these noms offer at least 25 percent of your DV:

Selenium supplements

We get that there are times when you can’t be picky about your nutrition. If you can’t access selenium-rich foods, selenium supplements might help once a doctor has confirmed that you’re deficient.

Your choices:

Never take a selenium pill without consulting a doctor!

Here’s why:

  • You can totally take too much selenium. You’ll know you’re overdoing it if you get a funky garlic or metallic taste in your mouth.
  • Selenium can interfere with some medications, including chemotherapy.
  • Supplements aren’t monitored as strictly as drugs. It’s always smart to run new supplements past your healthcare provider.

If your doctor thinks you need to up your selenium, they’ll probably suggest a diet change. If that doesn’t work, they’ll probably recommend a selenium supplement dose tailored to your needs.

Remember, selenium deficiency is rare. If you’re feeling exhausted or getting sick more often than normal, low selenium *could* be to blame… But you could also be deficient in another vitamin or mineral.

Some people do have a higher risk of deficiency than others.

  • Folks in low selenium regions. The selenium in your food comes from selenium in the soil. That means folks in low selenium regions are at a higher risk of deficiency. It’s a pretty rare issue in the United States.
  • Folks undergoing dialysis treatments. Research from 2009 indicated that dialysis removes some of the selenium from your blood. That *doesn’t* mean dialysis patients should start popping selenium pills though. Please consult with your doc first.
  • Folks who are HIV-positive. The National Institutes of Health reports that folks with HIV often also have selenium deficiencies. More research is needed to understand the link, but it’s definitely something to be aware of.

Who should take stock of their selenium?

Selenium deficiency is a rare health prob. You should sit up and pay attention to what your body might be telling you if you’re:

  • HIV-positive
  • undergoing dialysis or chemotherapy
  • pregnant
  • have a thyroid condition
  • live in an area known for low selenium soil

Only a doctor can determine if you have a selenium deficiency. It’s actually a tricky diagnosis because there’s no universal test for selenium.

To begin, your doc will probably ask about:

  • your health history
  • details about your symptoms
  • info on your daily diet

If they’re concerned about selenium deficiency, they’ll order one of these common ways to identify low levels:

  • glutathione peroxidase levels (an enzyme that needs selenium to function)
  • serum selenium concentrations in your blood or pee
  • selenium content in your hair or nails

Selenium deficiency is rare, but it can get serious if it goes unchecked. Folks with HIV, cancer, thyroid probs, and dialysis treatments are at the most risk for selenium deficiency. It can also be an issue if you live in a part of the world with low selenium soil.

Think your symptoms point to a selenium deficiency? Talk with your doctor. Because the symptoms are similar to other health probs, they’ll want to rule out other causes before recommending selenium supplements.