Selenium
Also known as: Selenomethionine, Sodium Selenite, Selenium Amino Acid Chelate, L-Selenomethionine
Selenium is a trace mineral essential for synthesizing selenoproteins, which function as antioxidant enzymes and support immune function. It plays a crucial role in thyroid hormone metabolism and reproduction. Selenium is vital for protecting cells from oxidative damage and infections.
Benefits
Powerful antioxidant protecting cells from free radical damage. Critical for thyroid health and proper hormone metabolism. Supports immune function and helps fight infections. May reduce inflammation and support joint health. Important for male fertility and reproductive health. May support cardiovascular health. May reduce cancer risk.
Recommended Dosage
RDA: 55 mcg/day for adults. Common supplement doses: 50–200 mcg daily. Upper limit: 400 mcg/day from all sources. Selenomethionine is better absorbed than inorganic selenium forms. Take with a meal containing fat for improved absorption. Works synergistically with vitamin E.
Food Sources
Brazil nuts (richest source), seafood (tuna, halibut, shrimp, salmon), mushrooms, eggs, chicken, turkey, whole grains, brown rice, oats, garlic, onions, sunflower seeds.
Side Effects
Well-tolerated at recommended doses. Selenium toxicity (selenosis) from excessive intake above 400 mcg: nausea, vomiting, diarrhea, brittle nails, hair loss, metallic taste, skin lesions. Chronic toxicity may cause tremors and nerve damage.
Interactions
Works synergistically with vitamin E to enhance antioxidant effects. Mercury may reduce selenium absorption and effectiveness. Interactions unlikely at recommended doses. May interact with certain cancer medications.
Warnings
Avoid Brazil nuts as primary source due to inconsistent selenium content and risk of overconsumption (single nut may contain 50+ mcg). Upper limit easily exceeded with whole foods. Those on chemotherapy should consult doctor before supplementing. Selenium may reduce seizure threshold.
Deficiency Symptoms
Keshan disease (heart disease from selenium deficiency). Kashin-Beck disease (joint and bone disease). Weak immune function. Hair and nail loss. Muscle pain and weakness. Thyroid dysfunction. Reproductive problems.
Frequently Asked Questions
What are the benefits of Selenium?▼
Powerful antioxidant protecting cells from free radical damage. Critical for thyroid health and proper hormone metabolism. Supports immune function and helps fight infections. May reduce inflammation and support joint health. Important for male fertility and reproductive health. May support cardiovascular health. May reduce cancer risk.
What is the recommended dosage for Selenium?▼
RDA: 55 mcg/day for adults. Common supplement doses: 50–200 mcg daily. Upper limit: 400 mcg/day from all sources. Selenomethionine is better absorbed than inorganic selenium forms. Take with a meal containing fat for improved absorption. Works synergistically with vitamin E.
What foods contain Selenium?▼
Brazil nuts (richest source), seafood (tuna, halibut, shrimp, salmon), mushrooms, eggs, chicken, turkey, whole grains, brown rice, oats, garlic, onions, sunflower seeds.
What are the side effects of Selenium?▼
Well-tolerated at recommended doses. Selenium toxicity (selenosis) from excessive intake above 400 mcg: nausea, vomiting, diarrhea, brittle nails, hair loss, metallic taste, skin lesions. Chronic toxicity may cause tremors and nerve damage.
What are the symptoms of Selenium deficiency?▼
Keshan disease (heart disease from selenium deficiency). Kashin-Beck disease (joint and bone disease). Weak immune function. Hair and nail loss. Muscle pain and weakness. Thyroid dysfunction. Reproductive problems.
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Supplement Disclaimer
This supplement information is for educational purposes only and should not replace professional medical advice. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a healthcare provider before starting any supplement, especially if you are pregnant, nursing, taking medications, or have a medical condition.