
Selenium Facts: Why Selenium is Important For Your Immune System
For most people, selenium isn’t on their radar the way that vitamin C, zinc and other immune-boosting supplements might be. But this powerhouse mineral has potent effects on your health. If you want a stronger immune system and improved wellness, here are the selenium facts you need to know.
What is Selenium and How Much Do You Need?

The best form, if you’re buying a supplement, is sodium selenate. In this form, your body can absorb nearly all of the selenium.
Selenium is an essential mineral that most people get through their food. Teenagers and adults need 55 µg of selenium a day, and people with chronic diseases like Crohn’s may be at a higher risk of being deficient in selenium.
Why does that matter? That’s because selenium plays several important roles in your body.
Selenium Facts: Deficiencies are linked to immune dysfunction
Researchers note that not having enough selenium in your system is linked with chronic inflammation and poorer immune responses. That may be because your immune system needs this mineral for the creation and activation of immune cells, and even antibody production.
Selenium Facts: Selenium works as an antioxidant
Selenium has proven antioxidant activity. Every day, your body is bombarded with free radicals that damage your cells. If left unchecked, this damage has been linked to increased risks of health issues like cancer, heart disease and even signs of premature aging in your skin (e.g. wrinkles, fine lines, sagging, etc.).
Selenium helps protect your cells, including the integrity and strength of your immune system’s cells.
Selenium Facts: The mineral may guard against cancer

A review of nearly 70 different medical studies found that cancer rates are lowest amongst people who eat or take a lot of selenium.
Every year, millions of us are impacted by cancer. Hundreds of thousands of people die from breast cancer, skin cancer, liver cancer and more. And the National Cancer Institute says that globally, the number of new cancer diagnoses will only continue to rise every year.
A review of nearly 70 different medical studies found that cancer rates are lowest amongst people who eat or take a lot of selenium, and may be especially helpful in specifically reducing your risks of prostate cancer, breast cancer, lung cancer and colon cancer.
In fact, selenium supplementation may even help to kill cancer cells.
Selenium Facts: Selenium may support thymus gland health
Selenium plays a role in a healthy thymus gland. And a healthy thymus gland produces thymic proteins, which help your immune system respond to threats.
And it’s not just selenium that’s important for your thymus gland and thymic protein levels. For example, BioProPlus-500 includes five bioidentical thymic proteins to support your immunity, and also includes the micronutrient zinc to support full-body wellness and help guard against free radical damage.
What to Eat to Boost Your Selenium Levels
You can find selenium supplements in most health food stores and natural health retailers.
The best form, if you’re buying a supplement, is sodium selenate. In this form, your body can absorb nearly all of the selenium. In contrast, your body can only absorb 50% of sodium selenite. Finally, selenium in the form of selenomethionine is the least desirable.
If you prefer to get your nutrients through whole foods the way that nature intended, you have several delicious options.
A handful of brazil nuts, for example, contains an incredible 543.5 μg of selenium. Other great sources of this essential mineral include:
- Fish (3 ounces of tuna offers 92 μg; halibut has 47.1 μg; Chinook salmon has 39.8 μg)
- Shellfish (3 ounces of raw Pacific oysters nets you 65.4 μg; you’ll get 47.1 μg from shrimp; and queen crab provides 37.7 μg)
- Seeds and grains (1/4 cup of sunflower seed kernels has 18.6 μg; a cup of brown rice has 19.1 μg; and a couple slices of whole-wheat bread provides 16.4 μg)
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