Is It Possible To Get Selenium Poisoning?

High blood levels of selenium (greater than 100 μg/dL) can result in a condition called selenosis. Symptoms of selenosis include gastrointestinal upsets, hair loss, white blotchy nails, garlic breath odor, fatigue, irritability, and mild nerve damage.

Selenium toxicity is rare but there have been a few reported cases that have been associated with industrial accidents and a manufacturing error that led to an excessively high dose of selenium in a supplement. The US Institute of Medicine of the National Academy of Sciences has said that the upper limit for selenium intake should be around 400 micrograms per day for adults to prevent the risk of developing selenosis.

It is more likely that animals develop selenium poisoning when grazing on plants that sequester selenium from the soil. A syndrome called 'blind staggers' may occur within a brief period (a few days to a few weeks) after the animal has begun to take in very high dietary levels of selenium. The symptoms of this condition are: impaired vision, a depressed appetite, and wandering in circles. Without removal of the high selenium intake, this can progress to varying amounts of paralysis and finally death from respiratory failure.

Animals can also develop alkali disease, a more chronic disease associated with lower level and longer duration intake of selenium. This is characterized by emaciation, loss of hair, deformation and shedding of hooves, loss of vitality and erosion of the joints of long bones.