Risks with High Doses

The UL for selenium is 400 mcg/day; toxicity is noted at mean doses greater than 800 mcg/day, with a 95% confidence limit of 600 mcg/day [62]. Doses above this range result in early symptoms of selenosis, including fatigue, irritability, and dry hair [6, 63, 64]. More advanced symptoms include dental caries, hair loss, loss of skin pigmentation, abnormal nails, vomiting, nervous system problems, and bad breath [63].