SeleniumSelenium is a mineral found in the soil and is important for many processes in the body. It is found in all parts of the body, but most of selenium is in kidney, liver, spleen, pancreas and testicles.

How does it work?

Selenium is an antioxidant and prevents DNA damaging caused by free radicals. It is an integral part of the antioxidant enzyme, glutathione peroxidase, which protects cells from environmental toxins and food. Selenium is often found in ”antioxidant cocktails” with vitamins C and E.

Such combinations can provide protection against many diseases caused by free radicals, such as cancer, heart disease, stroke, premature death and macular degeneration.

MAIN USEFUL EFFECTS: selenium is an interesting element because of its potential role in the fight against cancer. A five-year study conducted in the United States at Cornell University showed that taking 200 μg of selenium per day reduces the incidence of prostate cancer by 63 percent, colon and rectum cancer by 58 percent, malignant lung disease by 46 percent and total mortality of cancer by 39 percent.

In other studies, selenium has been shown to be a potentially useful substance in the prevention of ovarian, cervical, rectal, bladder, esophageal, pancreatic and liver diseases, but also leukemia. Studies have shown that tumors appear more frequent in people with the lowest levels of selenium in the blood; also, cancer recurrence and spreading is more frequent, and overall, survival is shorter compared to people with high levels of selenium.

Selenium may also have a protective effect on the heart, mainly becauase it reduces the possibility of blood clotting and the risk of clotting, so that the chance of a heart attack and stroke may be lower. This element increases the share of ”good” (HDL) cholesterol in the ratio with ”bad” (LDL), and this is unusually important for a healthy heart. The biggest benefit of selenium intake have smokers and people who have already experienced heart attack or stroke. But, this element in the form of vitamin and mineral nutrition supplements also protects the heart and blood vessels of all other people.

ADDITIONAL USEFUL EFFECTS: selenium can be useful in preventing the appearance of anorexia and macular degeneration, the main cause of visual impairment in elderly people. It is also necessary for the activation of thyroid hormone (from thyroxine to more active triiodothyronine), which are necessary for the work of each cell of our organism. This element is also important for the immune system and helps in protection against harmful bacteria and viruses, as well as cancer cells. Thus, selenium can be useful against viruses such as labial herpes and herpes zoster. Its effect against HIV virus is also investigated.

In combination with vitamin E, selenium has an anti-inflammatory effect. These two substances can help with chronic diseases such as rheumatoid arthritis, psoriasis, lupus and eczema.


The recommended daily dose is 75 μg for men and 60 μg for women. For therapeutic effect, it is necessary to take up to 200 μg per day.

IF YOU TAKE TOO LITTLE: the soil in the United Kingdom is not rich in selenium so, naturally, their food contains little selenium. Long term use of small amounts may increase the incidence of cancer, heart disease, difficulty with immunity and various inflammatory conditions, especially those that affect the skin. The consequences of insufficient selenium use during pregnancy may be anomalies (especially heart anomalies) or sudden infant death syndrome. Early signs of selenium deficiency are muscle weakness and fatigue.

IF YOU TAKE TOO MUCH: there will be no selenium overdose if you take it with food, but when using dietary supplements it is important to remember that the difference between the therapeutic (up to 350 μg) and the toxic dose (900 μg) is considerably lower than that of another dietary supplements. Symptoms of toxicity include nervousness, depression, nausea and vomiting, odour, hair loss and nail cracking.

How to take it?

DOSAGE: most nutritionists believe that the optimal dose for long-term selenium use is between 100 and 200 μg per day.

USE GUIDELINES: vitamin E greatly improves the effectiveness of selenium. Food rich in these vitamins is recommended to people with increased risk of heart disease.

Other sources

Food rich in selenium is Brazil nuts, seafood, poultry and meat. Significant amounts, depending on the composition of the soil, can sometimes be found in grains, especially oats and brown rice.

IMPORTANT: do not take doses higher than recommended: long term absorption of large doses of selenium (900 μg per day) can cause serious side effects such as rash, nausea, fatigue, hair loss, changes on nails and depression.