Brazil nuts

Brazil nuts are high in selenium and an ounce (roughly half a dozen) provides 800 micrograms. That's about double the US recommended tolerable upper limit. Overindulging regularly could lead to selenium toxicity. Symptoms may include a metallic taste, garlic odor on the breath, hair loss, brittle nails, fatigue, nausea, rash, diarrhea, runny nose, cough and nerve pain. Selenium-containing supplements are another potential source of this mineral.