[Selenium: benefits and risks].

Currently, the results of clinical studies suggest that an increase in the intake of selenium is associated with health benefits. However, the present emphasis should be on diagnosing and treating selenium deficiency resulting from a poor diet or disease. Here we have well-defined risk groups with a demonstrably elevated selenium requirement, and these patients must be provided with appropriate supplementation. On account of the toxic potential of this element, however, uncontrolled self-medication is not to be recommended. Until further studies have confirmed the data indicating a positive effect of selenium supplementation, this highly potent substance must be applied only with great caution and only selectively in specific situations.