Warning! Too Much Selenium Can be Toxic

Selenium is a trace element that’s found in the earth’s crust and in the soil. This mineral is needed in small amounts in the human body and has the important function of producing special antioxidant enzymes that protect cells against damage. It also helps to strengthen the immune system Its popularity as a supplement has grown in recent years after studies showed that it could reduce the risk of certain types of cancer. More recent studies looking at selenium and cancer prevention have called this protective effect into question. Still, many people take this supplement for cancer prevention purposes, and, unfortunately, some may be getting too much selenium.

How Much is Too Much Selenium?

Selenium is only needed in very small amounts by the body and it’s naturally found in a variety of foods. The best sources of selenium are Brazil nuts, sunflower seeds, molasses, and wheat germ. It’s also found in some meats and seafood as well as mushrooms and nuts. Some vegetables also contain selenium depending upon the soil they were grown in. The upper limit of selenium that’s safe for humans is 400 micrograms per day and some people are supplementing with as much as 200 micrograms in addition to what they get from diet – meaning they may be getting too much selenium.

What Are the Dangers of Too Much Selenium?

If a person takes in too much selenium on a daily basis, levels can gradually build up leading to selenium toxicity or selenosis.  In mild cases, the symptoms of selenosis are mild and include hair and fingernail loss, a garlic odor on the breath, stomach upset, mental changes, skin rash, and tingling in the hands and feet. In more severe cases of selenium toxicity, a person can develop fluid on the lungs, liver failure, and even death. Most of the severe cases of selenium toxicity have come from occupational exposure, but there it’s quite possible to develop selenium toxicity from taking supplements.

Is There Any Reason to Take a Selenium Supplement?

According to current research, you should only take a selenium supplement if you have a documented selenium deficiency. The health benefits of selenium – even for cancer prevention – are still not proven. There may be additional health risks as well. One study showed that taking selenium supplements of 200 micrograms per day increased the risk of type 2 diabetes. Most people get enough from their diet and shouldn’t take the risk of getting too much selenium by taking pills. It’s far less likely that you’ll get selenium toxicity when you get it from foods.

The Bottom Line

If you’re concerned about getting enough selenium in your diet, eat foods that are known to be high in selenium such as Brazil nuts and sunflower seeds. Don’t increase your risk of selenium toxicity by taking selenium supplements. This is another case where natural is better when it comes to nutrition.