Selenium
Also known as: Selenomethionine, Selenium Yeast
A trace mineral essential for thyroid function, antioxidant defense, and immune health.
What it is
Selenium is a trace mineral that functions primarily through selenoproteins — a family of proteins containing the amino acid selenocysteine. The body requires selenium in very small amounts, but deficiency has significant consequences for thyroid hormone metabolism, antioxidant capacity, and immune surveillance.
How it works
Selenium is incorporated into glutathione peroxidases (antioxidant enzymes), thioredoxin reductases (critical for cellular redox balance), and iodothyronine deiodinases (enzymes that activate thyroid hormone by converting T4 to T3). Without adequate selenium, thyroid function and antioxidant defense are compromised even when other nutrients are sufficient.
Clinical dose range
55–200 mcg/day
RDA is 55 mcg/day. Most research on antioxidant and thyroid benefits uses 100–200 mcg/day. Do not exceed 400 mcg/day — the margin between adequate and toxic intake is narrow.
Forms comparison
What to look for on the label
- Lists the specific selenium compound on the label
- Dose between 100–200 mcg (avoid products at or near 400 mcg UL)
- Third-party tested — soil contamination affects selenium content in food-based sources
- GMP certified, no unnecessary fillers
Health goals supported
Safety & dosing notes
The UL is 400 mcg/day. Selenosis (toxicity) causes hair loss, nail brittleness, and neurological symptoms. The therapeutic window is narrower than most minerals — accurate dosing is critical.
SuppsBuddy prioritizes selenomethionine and selenium yeast over inorganic forms and verifies that the dose sits within the safe and clinically relevant 100–200 mcg range.
Frequently asked questions
What is Selenium?
Selenium is a trace mineral that functions primarily through selenoproteins — a family of proteins containing the amino acid selenocysteine. The body requires selenium in very small amounts, but deficiency has significant consequences for thyroid hormone metabolism, antioxidant capacity, and immune surveillance.
How does Selenium work?
Selenium is incorporated into glutathione peroxidases (antioxidant enzymes), thioredoxin reductases (critical for cellular redox balance), and iodothyronine deiodinases (enzymes that activate thyroid hormone by converting T4 to T3). Without adequate selenium, thyroid function and antioxidant defense are compromised even when other nutrients are sufficient.
What is the typical clinical dose range for Selenium?
55–200 mcg/day. RDA is 55 mcg/day. Most research on antioxidant and thyroid benefits uses 100–200 mcg/day. Do not exceed 400 mcg/day — the margin between adequate and toxic intake is narrow.
What forms of Selenium should I look for?
Selenomethionine: Highest bioavailability (~90%); organic form well utilized by the body | Selenium Yeast: Natural, organic selenium; comparable to selenomethionine | Sodium Selenite: Inorganic form; effective but lower bioavailability and higher oxidative risk | Selenium Selenate: Inorganic, water-soluble; moderate bioavailability
Is Selenium safe?
The UL is 400 mcg/day. Selenosis (toxicity) causes hair loss, nail brittleness, and neurological symptoms. The therapeutic window is narrower than most minerals — accurate dosing is critical. This information is educational and is not medical advice.
How does SuppsBuddy evaluate Selenium?
SuppsBuddy prioritizes selenomethionine and selenium yeast over inorganic forms and verifies that the dose sits within the safe and clinically relevant 100–200 mcg range.
Related ingredients
This page is for educational purposes only. These statements have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before starting any supplement.