Selenium is a trace mineral that is essential for good health. It plays a key role in metabolism and thyroid function, and it helps protect your body from damage caused by oxidative stress. Selenium is also important for immune system function and DNA production.
How Much Selenium Do I Need?
The amount of selenium you need depends on your age and sex. Here are the daily recommended amounts:
- Birth to 6 months: 15 mcg
- Infants 7–12 months: 20 mcg
- Children 1–3 years: 20 mcg
- Children 4–8 years: 30 mcg
- Children 9–13 years: 40 mcg
- Teenagers 14–18 years: 55 mcg
- Adults: 55 mcg
- Pregnant women: 60 mcg
- Breastfeeding women: 70 mcg
What Foods Provide Selenium?
Selenium is naturally present in many foods and is added to some fortified foods. To ensure adequate selenium intake, include a variety of selenium-rich foods in your diet:
- Brazil nuts (one of the best sources of selenium)
- Seafood, including tuna, halibut, and sardines
- Organ meats, like liver
- Poultry and eggs
- Dairy products
- Whole grains and nuts
What Types of Selenium Supplements Are Available?
Selenium supplements come in different forms, each with unique properties. Here are some common types:
- Selenium Selenite: Often found in multivitamin and mineral supplements.
- Selenium Selenate: Similar to selenite, commonly included in dietary supplements.
- Selenomethionine: A highly absorbable form of selenium found in many standalone selenium supplements and multivitamins.
- Selenium Yeast: Contains selenium that is organically bound to yeast, often used in dietary supplements for its bioavailability.
Am I Getting Enough Selenium?
Most people get enough selenium through their diet. However, certain groups may be at risk of deficiency, including people with gastrointestinal disorders, those undergoing kidney dialysis, or those living in selenium-deficient regions. Ensuring adequate intake of selenium-rich foods or taking supplements can help maintain appropriate levels.
What Happens If I Don’t Get Enough Selenium?
Selenium deficiency can lead to a variety of health issues. It can impair immune function, cause fatigue and mental fog, and lead to muscle weakness. Severe deficiency is associated with heart disease (Keshan disease) and a type of arthritis (Kashin-Beck disease).
Groups More Likely to Have Low Selenium Intake:
- People living in regions with selenium-deficient soils
- Individuals with gastrointestinal disorders (e.g., Crohn’s disease, celiac disease)
- Patients undergoing kidney dialysis
- HIV-infected individuals
Effects of Selenium on Health
Selenium is being studied for its potential health benefits in various areas:
- Cancer Prevention: Some studies suggest that adequate selenium intake may lower the risk of certain cancers, such as prostate, lung, and colorectal cancer. However, more research is needed to confirm these findings.
- Thyroid Health: Selenium is crucial for proper thyroid function. It helps in the production and regulation of thyroid hormones.
- Cognitive Decline: Emerging research indicates that selenium might have a protective effect against cognitive decline and Alzheimer’s disease, though more studies are needed.
- Heart Health: Selenium's antioxidant properties may contribute to cardiovascular health by reducing oxidative stress and inflammation.
Can Selenium Be Harmful?
Selenium from food is generally safe and does not need to be limited. However, high doses of selenium supplements can lead to selenium toxicity, known as selenosis. Symptoms of selenosis include gastrointestinal distress, hair loss, white blotchy nails, and mild nerve damage. Chronic high intake can lead to more severe symptoms such as nausea, irritability, and fatigue.
Interactions with Medications:
Selenium supplements can interact with certain medications. For example:
- Anticoagulants and Antiplatelet Drugs: Selenium can increase the risk of bleeding when taken with these medications.
- Statins: Some evidence suggests selenium supplements might interfere with the effects of statin medications.
- Chemotherapy Drugs: Selenium might interfere with certain chemotherapy treatments.
Always consult with healthcare providers about dietary supplements to avoid potential interactions with medications.
Healthful Eating and Selenium:
A balanced diet that includes selenium-rich foods is the best way to ensure adequate selenium intake. Supplements can be beneficial in cases of deficiency or for those with increased needs, such as pregnant and breastfeeding women.
Additional Benefits and Considerations:
Recent studies highlight several interesting areas where selenium might play a role:
- Skin Health: Selenium's antioxidant properties can help protect skin from UV-induced damage, reducing the risk of skin aging and skin cancer.
- Fertility: Selenium is important for male fertility, as it plays a role in sperm motility and overall reproductive health.
- Antiviral Effects: Some research indicates that selenium may have antiviral properties, helping to protect against certain viral infections.
- Mood Regulation: Adequate selenium levels have been associated with improved mood and decreased risk of depression, though more research is needed to understand this relationship fully.
Food Sources of Selenium:
Here are some top sources of selenium:
- Brazil Nuts: The richest dietary source, providing more than the daily recommended amount in a single nut.
- Seafood: Fish such as tuna, halibut, and sardines are excellent sources.
- Organ Meats: Liver and other organ meats are high in selenium.
- Poultry: Chicken and turkey provide a good amount of selenium.
- Dairy Products: Milk, yogurt, and cheese contain selenium along with other essential nutrients.
- Whole Grains: Brown rice, whole wheat, and other grains are good plant-based sources.
Cooking and Selenium:
Cooking methods can impact the selenium content of foods. Here are a few tips for retaining selenium in your meals:
- Avoid Overcooking: Prolonged cooking can reduce selenium levels in food.
- Use Minimal Water: When cooking, use less water to retain more selenium and other minerals.
- Include Variety: A varied diet ensures you get selenium from multiple sources, reducing the risk of deficiency.
Special Considerations:
Certain groups may need to pay extra attention to their selenium intake:
- People in Selenium-Deficient Regions: Soil in some areas is low in selenium, affecting the selenium content of locally grown foods.
- Pregnant and Breastfeeding Women: Increased selenium needs during pregnancy and lactation require careful attention to diet or supplementation.
- Older Adults: Aging can affect selenium absorption and utilization, making it important for older adults to monitor their intake.
