The role of selenium in cancer and viral infection prevention.

The role of selenium, the essential trace mineral in human health and disease, is currently a subject of intense interest. The recent 30 years have been an exciting time in selenium research. Selenium has important health effects related to the immune response and cancer prevention, which are possibly not exclusively linked to their enzymatic functions. Selenium appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. An elevated selenium intake may be associated with reduced cancer risk. Large clinical trials are now conducted both in Europe and the USA to confirm or reject this hypothesis. In the context of health effects, low or diminishing selenium status in some parts of the world, notably in some European countries, is giving cause for concern.