 Garlic, onions, mushroom, broccoli, tomatoes, radishes, and Swiss chard may be good sources of selenium if the soil in which they are grown contains it.An individual will have to be monitored once they begin to take the selenium supplements, due to the fact that too much of it can cause balding, intestinal distress, weakness, and slow mental functioning.Individuals in China with the disease treat it with a herb called "Astragalus", which accumulates selenium from the soil.