As with many other important dietary minerals, despite its importance to health, the body does not need a considerable amount of selenium. That is why it is categorized as a trace mineral. Even though only small amounts are required on a daily basis, selenium is considered an essential mineral.
Here is what is known about the role selenium plays inside the body.
One of the most important characteristics of selenium, and many other vitamins and minerals, is that it acts as an antioxidant. Antioxidants protect the cells of the body from the damaging and potentially dangerous effects of free radicals. Over time, cells damaged by these free radicals can lead to the development of many illnesses and diseases including heart disease and cancer.
A versatile nutrient, selenium also plays a key role in keeping cell membranes healthy. That's very important since the cell membranes are responsible for the passage of vital nutrients into and out of all cells.
Furthermore, the pancreas could not function properly without selenium, nor could the thyroid gland...vital to energy and weight management. Another of the benefits of selenium is that it helps keep dandruff from becoming a problem. If a person already has dandruff, selenium may actually help it go away.
One interesting link that is being studied is the possible existence of a correlation between low selenium levels and people who have developed HIV/AIDS. At this time, it is still unclear whether lower levels of selenium lead to the development of this disease or whether low selenium levels are caused by one side effect of HIV/AIDS. The condition inhibits the body's ability to properly absorb nutrients...which, of course, includes vitamins and minerals.
Sources of Selenium
Available in many of our commonly consumed foods, such as, red meat, chicken, turkey, liver, fish, shellfish, dark green leafy vegetables, whole grains, eggs, onions, Brazil nuts, walnuts, brewer's yeast, wheat germ, pasta, noodles, rice, cottage cheese, cheddar cheese and garlic are all good sources of this mineral. Again, the body does not require a considerable intake of selenium, and consuming a nutritionally-balanced diet should provide all that is necessary.
The RDAs for selenium are as follows: 55 mcg/day for adult men and women, 60 mcg/day for pregnant women and 70 mcg/day for those who are breastfeeding.
It's important to note that too much selenium can be a problem. In the short-term, excess consumption of selenium may cause nausea, vomiting and diarrhea. Continued over longer periods, a condition called selenosis can develop and its symptoms include brittle finger and toenails, loss of hair and neurological problems including numbness and tingling in the extremities.
Since there are so many possible sources of this dietary mineral, a deficiency of selenium is very rare, especially for people who are adequately nourished. There are, however, some individuals who have gastrointestinal problems that cause malabsorption of this mineral, but that too is rare. A growing number of people have voluntarily subjected themselves to weight loss surgery, and, among this group there are often nutrient deficiencies due to the altered digestive system being unable to properly extract nutrients from the limited amount of food it can process.
Also rare, but nonetheless another possible cause for this type of deficiency, is one that occurs from the consumption of foods that have been grown in selenium-deficient soils. This does happen in some parts of the world, but does not seem to be a problem in developed countries.
As with any nutrient, extreme diets which drastically restrict total food intake, or the variety of foods eaten, can also produce a deficiency of selenium and almost any other nutrient.
Some of the symptoms of a selenium deficiency may include cardiovascular disease, nerve degeneration, hypothyroidism, arthritis, anemia and a dry, scaly scalp. A selenium deficiency may even increase the chances of developing some forms of cancer.
While selenium-specific supplements are not usually that common, or necessary, it is a common ingredient in many daily multivitamin supplements. It is also often found in combination with other vitamins or minerals, such as in the case of Shaklee's Vita-EŽ Plus Selenium.