Mineral
Selenium (as Sodium Selenite)
Also known as: sodium selenite, selenium oxide, inorganic selenium
Selenium (as sodium selenite) is an inorganic form of selenium with moderate bioavailability, essential for glutathione peroxidase and thyroid hormone metabolism. Selenomethionine (organic form) is better absorbed.
Primary uses
- antioxidant defense
- thyroid function
- reproductive health
- immune support
How it works
- component of selenoproteins (glutathione peroxidase, thioredoxin reductase)
- supports thyroid hormone conversion
- reduces oxidative stress
Dosage
- Typical range
- 55–200 µg daily
- Timing
- can be taken anytime; consistent daily intake recommended
- With food
- May be taken with or without food
- Duration
- Safe long-term; avoid exceeding UL of 400 µg daily to prevent selenosis
- Special populations
- Brazil nuts naturally very high in selenium; adjust supplemental intake accordingly
Forms
- sodium selenite· 70/100
Safety
Common side effects
- garlic-like body odor (at higher doses)
- brittle nails
- hair loss (at excessive doses)
Contraindications
- history of selenosis
Evidence notes
Selenium has good evidence for thyroid and antioxidant support; inorganic selenite form has lower bioavailability than organic selenomethionine.
Grade B: Some human trials support key claims; further confirmation needed.
Related in Mineral
Check a full stack
Formulate's free interaction checker lets you paste in any combination of supplements and medications at once — every pairing flags severity, timing, and cited evidence.
Open the checkerMedical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider.