By John Sherman, ND
A 2025 study published in the European Journal of Nutrition found that both Brazil nut butter and selenium supplements effectively increased selenium levels, regardless of whether participants followed a vegan or omnivorous diet.
This suggests that Brazil nuts can be a viable whole-food alternative to supplementation for boosting selenium intake.
Selenium is an essential trace mineral involved in thyroid hormone synthesis, immune function, cancer prevention, and male fertility.
On average, a single Brazil nut contains between 75 and 100 micrograms of selenium.
To match the typical 200-microgram dose found in many supplements, just two to three Brazil nuts per day may be sufficient.
In my clinical practice, I often recommend selenium to support thyroid function—particularly for enhancing the conversion of T4 to T3 in peripheral tissues.
Many patients express fatigue over taking multiple supplements, so I’m always glad to offer a food-based solution when possible.
Brazil nuts provide a simple, natural, and effective way to meet this important nutritional need.
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John Sherman, ND, is a writer at Green Medicine Newsletter. Reprinted with permission.
Simon R, Lossow K, Pellowski D, et al. “Improving the selenium supply of vegans and omnivores with Brazil nut butter compared to a dietary supplement in a randomized controlled trial.” Eur J Nutr. 2025;64(2):74. Published 2025 Feb 1. doi:10.1007/s00394-025-03587-z
