Causes of selenosis range from ingestion of excessive selenium, as is the case of regular snacking on Brazil nuts which could contain up to 90 µg of selenium per nut. There are also many other plants that have the capability to concentrate selenium that is taken up from the soil, which are termed selenium accumulators.
Selenium toxicity can occur with acute or chronic ingestion of excess selenium. Symptoms of selenium toxicity include nausea; vomiting; nail discoloration, brittleness, and loss; hair loss; fatigue; irritability; and foul breath odor (often described as “garlic breath”). Selenium is found in the environment in soil.
Why Are Brazil Nuts High in Selenium? Brazil nuts are well known for their high concentration of selenium. Soil conditions in parts of South America are unique in that they are deficient in sulfur, a necessary element required for the formation of the amino acids methionine and cysteine [1]
Just one Brazil nut contains 96 micrograms of selenium, almost twice your daily requirement. Doctors advise eating no more than five Brazil nuts a day to avoid potential health risks like selenium toxicity. This condition is linked to breathing problems, heart issues, and kidney failure.
Brazil nuts, seafood, meat, poultry, and organ meats are the richest food sources of selenium. Other sources include cereals and other grains, and dairy products [6]. The amount of selenium in drinking water is not nutritionally significant in most geographic regions [3,13].
Extremely high intakes of selenium can cause severe problems, including difficulty breathing, tremors, kidney failure, heart attacks, and heart failure. The daily upper limits for selenium include intakes from all sources—food, beverages, and supplements—and are listed below.
You should not take selenium without talking to your doctor if: You have an underactive thyroid (hypothyroidism) You have had skin cancer. You are at risk for skin cancer.
Glutathione peroxidase and the deiodinases, the selenium-dependent enzymes, are impaired in selenium deficiency. This leads to accumulation of peroxidases, which can damage the thyroid, whereas deiodinase deficiency impairs thyroid hormone synthesis.
Selenium levels can be tested in the blood. The reference range for serum selenium levels is 120-160 micrograms/liter, although this may vary between labs. Additionally, selenium is found on micronutrient panels such as the Micronutrient Test by SpectraCell Laboratories.
Bananas offer a wide range of health benefits and are a great source of selenium. Including a banana in your daily diet can contribute to your selenium intake, providing approximately 1.2 mcg.
So enjoying a few Brazil nuts each day is safe – just avoid eating excessive amounts all at once! Did you know? The daily selenium target (RDI) can be achieved with just two Brazil nuts. And around seven Brazil nuts provides the upper limit for selenium (400µg/day).
When taken by mouth: Selenium is likely safe when taken in doses less than 400 mcg daily, short-term. But selenium is possibly unsafe when taken in high doses or for a long time. Taking doses above 400 mcg daily can increase the risk of developing selenium toxicity.
The presence of specific symptoms such as rheumatoid arthritis, abnormally shortened fingers and toes, or growth disorders in areas characterized by selenium-deficient soil should raise heightened suspicion of selenium deficiency. This is particularly relevant when evaluating children between the ages of 5 and 13.
Eating too many Brazil nuts can lead to toxic levels of selenium in the body (selenosis) and cause symptoms such as bad breath, diarrhea, nausea, skin rashes/lesions, nerve pain and fatigue. In rare cases, very high levels can cause kidney failure, cardiac arrest and even death.
Our bodies need selenium to work well, but there are risks to adding more to your diet, including: Side effects. Taken at normal doses, selenium doesn't usually have side effects. An overdose of selenium may cause bad breath, hair loss, fever, tiredness, and nausea.
