Trace minerals like selenium are essential for health, but they often fly under the radar.
Today, we’ll cover all you need to know about selenium, named after Selene, The Roman Goddess of the moon. If you learn nothing else from this article, at least that fun fact may help at your next quiz night.
Selenium is an essential trace mineral that plays a vital role in various enzymatic processes in the body. As with all essential nutrients, your well-being depends on having enough selenium.
The word essential (in this context) means selenium must be consumed daily via diet or nutritional supplements. It’s not made in the body.
Brazil nuts are probably the most well-known source of selenium, but you can also get it from eggs, fish, organ meats, brown rice, and Brewer’s yeast.
Selenium is a “Goldilocks” nutrient – you need your levels to be just right. Too much or too little selenium can be disastrous for health.
Your body uses selenium to activate specific proteins – called selenoproteins – which act as antioxidants in the body.
One of these selenoproteins is glutathione peroxidase, the body’s “master antioxidant” (we’ve also written about glutathione). Each glutathione molecule requires four selenocysteine molecules (selenium bound to the amino acid cysteine).
In short, your body needs selenium to defend your cells from free radicals and keep your metabolism functioning smoothly.
Your thyroid is a small, butterfly-shaped gland in the throat that produces hormones that control your metabolism. If your body were a steam train, your thyroid is the furnace.
The thyroid contains more selenium than any other gland or organ in the body. It’s crucial for regulating thyroid hormones. In fact, low selenium levels may cause thyroid conditions.
Studies have shown selenium may promote heart health.
This is likely due to selenium’s antioxidant properties. This may protect against hardening of the arteries by limiting oxidative damage and blood vessel inflammation.
However, a conflicting study found that selenium reduced inflammation but didn’t have other heart health benefits. This suggests the benefits of supplementing are more pronounced in selenium deficient people.
Selenium is in many common foods. So, why the heck do you need a supplement?
Well, many people don’t, so I’m not suggesting everyone should take a supplement.
That said, in many areas of the world, selenium levels in the soil are dismally low due to over-farming.
Some people also struggle to maintain healthy selenium levels. This includes people on restrictive diets (hello vegans), HIV-positive people, people with kidney disease, and those with Crohn’s disease or ulcerative colitis. Certain medications – like steroids, antacid medication, and birth control pills – may deplete your selenium levels.
Even a mild selenium deficiency can play havoc with your well-being. But whether you’ll benefit from a supplement depends on your diet, lifestyle, and health history.
Selenium is widely available as a standalone supplement or as part of a formula.
With literally hundreds of selenium supplements available, I’ve selected the most bioavailable selenium products on the market. I’ve done my due diligence to ensure they’re made according to strict manufacturing standards.
*Note: We do have affiliate links throughout this article, which means we receive a commission if you purchase from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying things like banner ads. Those suck.
Codeage strives to develop science-backed longevity supplements. They use liposomal delivery systems to ensure your cells absorb and use the nutrients efficiently.
A liposomal delivery system means that the molecules are protected in a layer of fatty acids called “liposomes” so that the selenium can make it through the harsh environment of the stomach and get absorbed into your bloodstream.
Their selenium supplement provides 200 mcg of L-Selenomethionine per capsule. L-Selenomethionine is the most absorbable form of supplemental selenium. It’s wrapped in a liposomal delivery matrix, making it easier for your cells to recognize and incorporate.
This product grabs the top spot because it’s the most bioavailable supplement on the list, and one bottle will last 6-months. It’s also 100% vegan, non-GMO, and free from dairy, soy, and gluten.
Codeage has some of the strictest production and testing standards around. All their products are third-party tested and manufactured in FDA-approved cGMP facilities.
Life Extension is among the best in the game for anti-aging supplements.
Their Super Selenium Complex provides a 200-mcg blend of three different forms of selenium:
You also get 20.1 mg of the antioxidant vitamin E, which is known for protecting cell membranes from free radical damage. This study found vitamin E may work synergistically with selenium to inhibit prostate cancer cell growth.
Life Extension products are third-party tested and come with Certificates of Analysis (COA).
Thorne Research understands that trace minerals work best in synergy. They’ve created Pic-Mins, a trace mineral formula containing zinc, selenium, chromium, manganese, molybdenum, boron, and vanadium.
They deliver the most absorbable forms of nutrients in their products. This formula contains 100 mcg of selenium as bioavailable selenomethionine.
Thorne complies with the Current Good Manufacturing Practices (cGMP) set by the FDA. Each product goes through four rounds of thorough testing to verify identity, potency, and purity.
Thorne offers the same bioavailable, third-party-tested selenium as a standalone supplement. Each capsule offers 200 mcg of selenomethionine. It’s also free from additives, gluten, soy, and GMOs.
California Gold Nutrition Immune 4 is an immune-boosting formula that combines four clinically studied ingredients.
Each capsule features 50 mcg of selenium (as selenomethionine), 500 mg of vitamin C, 1000 IU of vitamin D3, and 10 mg of zinc.
These ingredients work synergistically to defend your body from oxidative damage and regulate your immune system. It’s a supplement you can take year-round or when you need extra support during winter.
California Gold products are third-party tested and made in a cGMP-certified facility.
NOW Selenium is a yeast-free, non-GMO supplement, providing highly absorbable L-selenomethionine at a great price.
It comes in 100 mcg tablets or 200 mcg vegetable capsules. And you choose between bottles of 100, 180, or 250 servings.
NOW Foods has been around for decades, and they exceed the standards set for cGMP by the FDA.
Pure Encapsulations Selenium is simple but powerful. It offers 200 mcg of selenomethionine per serving and comes in either 60 or 180 capsules. This works out to 18-20 cents per serving! It’s vegan-friendly, non-GMO, and certified gluten-free.
Healthcare practitioners love Pure Encapsulations due to their strict quality standards and bioavailable formulas.
Nature’s Way Selenium provides 200 mcg of yeast-free selenomethionine per capsule.
Nature’s Way has been making quality nutritional supplements for over 50 years. They are also eco-conscious, using 97% post-consumer recycled materials to make each bottle.
We chose what we believe are the best selenium products on the market, but you need to make the best decision for your needs.
Here’s how we ranked these products.
The FDA doesn’t regulate the supplement industry. This gives dodgy companies free rein to make false claims on their supplement labels.
It’s crucial you buy selenium from a trusted brand because high levels of selenium are dangerous for your health.
We only chose companies that are cGMP-certified and third-party tested to evaluate the purity, dose, and quality. Plus, we boost companies who make their test results public.
The supplements on the list all contain organic selenium, known as selenomethionine. It has a significantly higher absorption rate compared to other forms.
We also prioritized supplements using enhanced delivery mechanisms – like Codeage’s liposomal delivery.
Selenium is a trace mineral, so your body only needs small amounts to function well.
Most studies used between 100-300 mcg of selenium daily. We ensured the products on this list give you a therapeutic dose while still being safe.
Quality selenium supplements don’t have to break the bank. We chose high-quality supplements that are also affordable.
Some studies have found higher selenium levels are associated with a lower incidence of cancer – particularly breast, prostate, lung, esophageal, and gastric cancers.
Selenium supplementation may also improve quality of life in those going through radiotherapy.
However, other studies have found no significant link between selenium and cancer outcomes. So, the evidence for selenium preventing and treating cancer isn’t strong enough to make any claims.
Selenium plays a vital (but indirect) role in detoxification. As mentioned, selenium is needed to form the selenoprotein glutathione. And glutathione neutralizes toxins during phase II liver detoxification.
This study found that 100 mcg of selenium daily over three months improved mercury excretion in people with years of environmental mercury exposure.
This study found taking 100 mcg of selenium daily improved mood and anxiety levels. However, the study was small, so the jury is still out until we have newer, more detailed studies.
Some symptoms of low selenium may include:
It’s always best to check with a doctor if you suspect a selenium deficiency. They can check your levels using a blood test or hair mineral analysis.
The daily value (DV) for selenium for people over 14 years is 55 mcg. This jumps to 60 mcg for pregnant women and 70 mcg for lactating women.
However, I have beef with the DV. It’s the bare minimum you need to avoid deficiency. So, for optimal health, you probably need more.
The tolerable upper limit (UL) for adults is around 400 mcg, which seems safe for most people.
Consuming selenium supplements at safe doses is well-tolerated. However, too much selenium can become toxic.
Although rare, selenium toxicity – known as selenosis – may cause:
Speak to your doctor before taking a selenium supplement, and always stick to the recommended daily dose.
If you choose to take a selenium supplement, picking one from the list above ensures you get a quality product containing exactly what it says it does.