Selenium is a trace element required by our bodies in small amounts for proper functioning. It serves as a cofactor for several antioxidant enzymes, which are proteins that help neutralise harmful free radicals in our cells. Selenium is also crucial for the synthesis of thyroid hormones, which regulate various physiological processes, including metabolism and growth.
Functions of Selenium
- Antioxidant defence: Selenium is a crucial component of several antioxidant enzymes, such as glutathione peroxidase, which help protect cells from damage caused by reactive oxygen species.
- Thyroid function: Selenium is involved in the synthesis of thyroid hormones, which are essential for regulating metabolism, growth, and development.
- Immune function: Selenium supports the proper functioning of the immune system by enhancing the activity of certain immune cells and modulating the production of inflammatory molecules.
- Reproductive health: Selenium is essential for the maintenance of fertility and the proper functioning of the reproductive system.
Good Sources of Selenium
Selenium can be found in various food sources, both plant-based and animal-based. These include:
- Brazil nuts: One of the richest sources of selenium, just a few nuts can provide the daily recommended intake.
- Seafood: Fish, such as tuna and salmon, and shellfish, like shrimp and crab, are excellent sources of selenium.
- Meat and poultry: Chicken, turkey, and beef contain moderate amounts of selenium.
- Eggs and dairy products: Eggs, milk, and yogurt provide some selenium.
- Whole grains: Brown rice, whole wheat bread, and oatmeal contain trace amounts of selenium.
How Much Selenium Do We Need?
According to the National Institutes of Health (NIH), the recommended daily intake of selenium varies depending on age, sex, and life stage. Here are some general guidelines:
- Infants 0-6 months*: 15 mcg/day (micrograms)
- Infants 7-12 months*: 20 mcg/day
- Children 1-3 years: 20 mcg/day
- Children 4-8 years: 30 mcg/day
- Children 9-13 years: 40 mcg/day
- Adolescents 14-18 years: 55 mcg/day
- Adults 19 years and older: 55 mcg/day
- Pregnant women: 60 mcg/day
- Breastfeeding women: 70 mcg/day
* The values for infants are adequate intake (AI)
It’s essential to consult with a healthcare professional to determine your specific selenium needs.
What are the Signs of Selenium Deficiency?
Selenium deficiency is relatively rare but can occur under certain circumstances. Some common signs and symptoms include:
- Muscle weakness and pain
- Hair loss
- Weakened immune function
- Mental fog and confusion
In severe cases, selenium deficiency can lead to a disorder called Keshan disease, which affects the heart muscle and can cause heart failure.
If you suspect you may be deficient in selenium, it’s essential to consult a healthcare professional for proper evaluation and treatment.
What Happens If I Take Too Much Selenium?
Excessive selenium intake can lead to selenium toxicity, which can cause various symptoms and complications. Some common signs of selenium overdose include:
- Nausea and vomiting
- Hair and nail loss
- Skin rashes
- Irritability and nervous system abnormalities
It’s essential to follow the recommended daily intake guidelines and consult with a healthcare professional before taking selenium supplements, as excessive selenium intake can be harmful.