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Selenium — Frequently Asked Questions

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Frequently Asked Questions

Can I get enough selenium from Brazil nuts?

Yes. Brazil nuts are the richest food source of selenium, containing 68-91mcg per nut on average. Just 1-2 Brazil nuts daily provides adequate selenium for most adults. A 2008 Thomson et al. study confirmed that 2 Brazil nuts daily was as effective as 100mcg selenomethionine supplement for raising selenium status.

Does selenium help with thyroid problems?

Selenium is essential for thyroid hormone metabolism. For Hashimoto's thyroiditis specifically, multiple studies show 200mcg daily reduces TPO antibodies. However, evidence that this translates to improved thyroid function or reduced medication needs is less consistent. Selenium is most beneficial for thyroid patients who are selenium-deficient.

How much selenium is too much?

The upper limit is 400mcg/day. Chronic intake above this causes selenosis, characterized by garlic breath, hair loss, nail changes, fatigue, and gastrointestinal problems. Acute toxicity is possible above 1,000mcg. If eating Brazil nuts, limit to 2-3 per day as selenium content varies widely.

Full Selenium Guide

References

  1. (). Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. DOI
  2. (). Selenium supplementation significantly reduces thyroid autoantibody levels in patients with chronic autoimmune thyroiditis: a systematic review and meta-analysis. Thyroid. DOI
  3. (). Brazil nuts: an effective way to improve selenium status. American Journal of Clinical Nutrition. DOI