Are selenium supplements needed (by the general public)?

Selenium is an unusual trace element, since both toxicities and deficiencies are known to occur in animals in the United States under natural conditions. Such extremes in the selenium intake of animals are due to the fact that the plants consumed by the animals are often of local origin and there are great geographic variations in the amount of selenium in the soil that is available for uptake by the plants. In contrast to animals, the human population generally draws its foods from several different regions of the country. There is no evidence at this time to suggest that the food supply in the United States contains either too little or too much selenium. There is reason, however, to suspect that indiscriminate selenium supplementation of the diet is potentially hazardous. A well balanced diet is the best way to obtain not only selenium but all of the other nutritionally essential trace elements as well.