Selenium what is it good for

The following foods are good sources of selenium:. The recommended DV for selenium is 55 mcg per day for most adults. During pregnancy, a person should consume 60 mcg, and while lactating, they should consume 70 mcg per day. Selenium deficiency is rare worldwide, and it often takes years to develop. It usually only occurs in regions with severely low selenium content in the soil, such as several regions in China.

However, according to the ODS , supplementation programs have mostly eradicated these deficiencies in the Chinese population. The upper limit for the optimal level of selenium in the body is mcg for adults. It is rare for anyone to overdose on selenium, especially from selenium in food. However, an overdose of highly concentrated supplements can have negative effects.

These may include :. In extreme cases, selenium overdose could lead to kidney failure, heart failure , and death. Selenium supplements can also interact with some medications, including cisplatin, which is a chemotherapy drug. The use of this drug can reduce selenium levels in the body. People can get selenium through multivitamins and other dietary supplements. These may contain the mineral in different forms, including selenomethionine and sodium selenate.

The Dietary Guidelines for Americans, — encourage people to get their nutrients from food sources rather than supplements. Eating a varied and healthful diet is more important than concentrating on individual nutrients as the key to good health.

When taking any supplement, it is important to purchase it from a reputable source. Selenium supplements are available for purchase online. Selenium is a mineral that may provide different health benefits. For example, it may help with cardiovascular health, cognitive function, and thyroid health. People can get selenium from foods that contain it, and they can also add it to food or consume it as a supplement.

However, more research is needed to determine whether or not taking selenium supplements can actually reduce disease risk or help prevent health problems. The best sources of selenium include some nuts, fish, and poultry. Address psychological issues like stress, sleep, and exercises before turning to supplements.

Studies of selenium levels and large populations over time have found a correlation between people who eat a lot of selenium and a lower risk of some cancers, specifically bladder cancer, prostate cancer, lung cancer and some gastrointestinal cancers. More than small animal experiments have shown selenium supplements reduce the number of new tumors, according to a January review published in the British Journal of Nutrition.

Regions with selenium-rich soil tend to have lower death rates from cancer than areas with low-selenium soil, particularly for cancers of the lung, esophagus, bladder, breast, colon, rectum, pancreas, ovary and cervix, according to the American Cancer Society. But these trends do not prove selenium is an underlying factor in cancer survival.

Controlled studies, in which groups of people were given either selenium supplements or a placebo, have found conflicting results about selenium's cancer fighting properties.

A study of more than 1, men and women with non-melanoma skin cancer found that the group of men assigned to take selenium supplements also had 52 percent fewer cases of prostate cancer, according to the paper published in the journal BJUI.

The Mayo Clinic does not recommend selenium supplements for cancer based on the current scientific evidence. Preliminary studies show selenium may play a role in heart health. Selenium reduces inflammation and prevents platelets — a type of clotting cell in the blood — from aggregating, which is necessary for blood clots to form. Blood clots can lead to stroke, heart attacks , kidney failure, pulmonary embolism and other problems.

A selenium deficiency may make atherosclerosis a hardening of the arteries worse, according to the University of Maryland Medical Center. Animal studies have shown supplementing selenium after a long dietary deficiency reversed cardiovascular damage in mice.

However, human studies on the subject have seen mixed results. Some observational studies, where doctors track people but don't randomly assign them to taking a supplement or a placebo, found that the lower the selenium levels in the blood, the higher a person's risk of high blood pressure and coronary heart disease.

But other observational studies didn't find a significant link between selenium levels and cardiovascular disease. Some observational studies even found the opposite trend; higher selenium levels were associated with worse cardiovascular health, according to the National Institutes of Health NIH. In one clinical trial, researchers assigned more than older adults to take either a placebo or various strengths of selenium supplements for six months. They found the people taking selenium supplements had lower levels of bad cholesterol, and the group taking the highest amount of selenium micrograms also showed higher levels of HDL "good" cholesterol, according to a May paper in the Annals of Internal Medicine.

However, a review by the Cochrane Collaboration concluded that taken together, the evidence from selenium studies — including nearly 20, people participating in 12 trials — did not support taking selenium supplements as a way to prevent major cardiovascular disease. However, the researchers did note that the vast majority of participants were men from the United States, where people already get a lot of selenium from food. People with rheumatoid arthritis are more likely to have low selenium levels, but it is currently unclear whether low selenium levels are a result of the condition, or a contributing factor.

Once a person is diagnosed with rheumatoid arthritis, selenium supplements do not seem to help, according to the University of Maryland Medical Center. Because selenium levels decline with age, there is a possibility that selenium influences age-related mental decline. Large observational studies have found either no link between selenium levels and memory test scores, or found that people with lower selenium levels are more likely to have cognitive decline over time, according to the NIH.

One eight-year study of more than 4, participants, ages 45 to 60, found that people taking antioxidant supplements had better verbal memory scores six years after the study ended, according to the September paper in the American Journal of Clinical Nutrition. However, because the antioxidant supplements included a mix of vitamin and minerals, the researchers could not separate what, if any, influence selenium had on memory scores.

Selenium may have a role in cognitive decline because of its antioxidant properties, which can protect brain cells from damage over time. But overall, the limited number of studies on selenium and mental decline do not provide enough evidence to determine whether selenium can influence brain function, according to the NIH.

Evidence supports a link between selenium levels, iodine deficiencies and thyroid function, especially in women. Selenium is more concentrated in the thyroid than in other organ in the body, and it is important in the production and metabolism of thyroid hormone.

One analysis of 1, people in France found that among women a mild iodine deficiency, those with lower the selenium levels were more likely to develop goiters or thyroid damage compared with those with higher selenium levels, according to a article in the European Journal of Endocrinology. Subsequent studies have found similar links. However, controlled studies on thyroid health, where participants are given selenium supplements or placebos, have had mixed results.

More research is needed to determine if selenium supplements can fight thyroid diseases. Selenium benefits are especially helpful if you have a weak immune system or a history of cancer in your family. Supplementation at high doses has been shown to potentially have anti-cancer effects. According to studies, it may be effective at reducing the risk of cancer incidence, cancer-caused mortality and severity of cancers — specifically in the liver, prostate, colorectal and lungs.

Because it has the special job of activating selenoproteins, this mineral acts in an enzymic role that helps antioxidants to do their job best. There is evidence that selenium benefits include not only being able cut cancer risk, but also help to slow down existing cancer progression and tumor growth. Studies have shown that a high dose of milligrams a day can be effective in protecting DNA, which can reduce the risk for cell mutation and cancer development.

Other studies show that in areas of the world where the soil is lowest in selenium, cancer risk is increased when compared to areas that have higher levels naturally available.

According to recent research, selenium benefits immunity because it is needed for the proper functioning of the immune system and can also be a key nutrient in counteracting the development of viruses, including HIV. Low selenium concentrations are associated with an increased risk of cardiovascular disease. Supplements or an increase of selenium-rich foods may be able to help prevent coronary heart disease. Research now suggests that there is a link between thyroid metabolism and selenium deficiency.

This mineral acts as a catalyst for the production of active thyroid hormones. The thyroid gland controls numerous important everyday body functions, including appetite, sleep, temperature, weight, energy and more.

A problem with proper thyroid function can result in negative symptoms, such as irritability, muscle weakness, fatigue, weight gain or loss, trouble sleeping, and many other reactions — therefore acquiring proper amounts of selenium benefits the thyroid and body in many important ways. It acts as a powerful protector of the thyroid, and it regulates the production of reactive oxygen within the gland and protects it from antibodies that can create thyroid disease.

Certain studies have investigated the use of selenium for the treatment of dozens of conditions that range from asthma to arthritis, thyroid disorder and heart disease. The risk of these conditions increase as we age, so consuming it can help defend the body and may contribute to a longer life.

Observational studies have demonstrated that patients with chronic asthma may have lower levels of selenium. According to studies, when people with asthma took selenium supplements, they experienced less asthma-related symptoms than those who took a placebo.

Experts think that supplementation may be a useful add-on treatment to medication for patients with chronic asthma. It appears that both low and high sperm selenium concentrations can have a negative influence on the number of sperm, therefore aiming to meet the recommendation, but not to far exceed it, is important for fertility.

Some studies also show that this may even reduce the risk of miscarriage, but at this point more research has been dedicated to infertility in men than in women when it comes to selenium supplementation. Selenium is a trace mineral, which means we only need a small amount of it. Some doctors, such as naturopaths , may recommend selenium supplements to treat acne, asthma, tendinitis, male infertility problems and postmenopausal disorders in women, among other conditions.

It is important to note that if you already consume proper amounts of selenium from a healthy diet, consuming more may not be beneficial, and high doses reaching micrograms can even be harmful. The recommended daily allowance for selenium depends on your age and is as follows, according to the USDA :.

In supplement form, selenium is available in the form of selenomethionine and selenium selenite. Selenomethionine is usually easier for most people to digest and absorb properly. When taking selenium supplements, most adults should take up to 55 micrograms daily such as of selenomethionine , while pregnant women can take up to 60 micrograms and lactating women can take up to 70 micrograms. No one should exceed recommendations by supplementing with very high doses without consulting a physician.