Selenium
Selenium is a trace mineral incorporated into selenoproteins including iodothyronine deiodinases that convert T4 to active T3, and glutathione peroxidases that protect the thyroid from oxidative stress. Deficiency impairs thyroid hormone conversion and may worsen autoimmune thyroid disease, while excessive supplementation is toxic. Brazil nuts, seafood, and organ meats are dietary sources.
1 providers include this
Thyroid Function
70-150 μg/L
What is Selenium?
Selenium is a trace mineral incorporated into selenoproteins including iodothyronine deiodinases that convert T4 to active T3, and glutathione peroxidases that protect the thyroid from oxidative stress. Deficiency impairs thyroid hormone conversion and may worsen autoimmune thyroid disease, while excessive supplementation is toxic. Brazil nuts, seafood, and organ meats are dietary sources.
Why It Matters
Essential for thyroid hormone conversion and antioxidant protection. Deficiency impairs thyroid function. Important for autoimmune thyroid disease.
Which Providers Test Selenium?
Full Provider Comparison
| Provider | Includes | Annual Cost | Biomarkers |
|---|---|---|---|
 Superpower | — | $199 | 100+ (150 with ratios) |
 WHOOP Advanced Labs | — | $349 | 65 |
 Labcorp OnDemand | — | $398 | 40+ |
| — | $486 | 40+ | |
| — | $449 | 288 | |
| — | $349 | 100+ | |
| — | $829 | 54 | |
 Function Health | ✓ | $365 | 160+ |
| — | $250 | 65 | |
| — | $495 | 80+ | |
| — | $895 | 100+ | |
| — | $1950 | 130+ | |
| — | $375 | 95+ | |
| — | $Varies | 75+ | |
| — | $190 | 100+ | |
| — | $99 | 50 | |
| — | $124 | 60 | |
| — | $349 | 130+ | |
| — | $349 | 80+ | |
| — | $375 | 85 | |
| — | $700 | 128 | |
| — | $99 | 100+ |
Frequently Asked Questions
What is Selenium?
Selenium is a trace mineral incorporated into selenoproteins including iodothyronine deiodinases that convert T4 to active T3, and glutathione peroxidases that protect the thyroid from oxidative stress. Deficiency impairs thyroid hormone conversion and may worsen autoimmune thyroid disease, while excessive supplementation is toxic. Brazil nuts, seafood, and organ meats are dietary sources.
What is the optimal range for Selenium?
The standard reference range for Selenium is 70-150 μg/L. Optimal ranges may differ based on individual health goals and expert recommendations.
Which blood test providers include Selenium?
1 out of 22 blood testing providers include Selenium in their panels. This biomarker has limited availability.
What category does Selenium fall under?
Selenium is categorized under Thyroid Function. This category includes biomarkers that help assess related aspects of health and wellness.
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Medical Disclaimer
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
Last reviewed:2026-04-12