Background: The trace mineral selenium (Se) is a crucial nutrient for human health and its deficiency is considered to be important in various types of cancer. This element is a component of some important selenoproteins and enzymes required for main functions in organisms as antioxidant defense, reduction of inflammation, thyroid hormone production, DNA synthesis, fertility, reproduction and killing cancer cells (by reducing the blood supply to tumors). It has been found that a low level of Se in diet has an effective role in increasing risk of cancers by the mechanism of protein synthesis inhibition or specified enzymes by the cancerous cells stimulating the cell death.

Materials and Methods: Databases of Pubmed, ScienceDirect, Springer and Google scholar were searched in order to achieve the related articles.

Results: Therefore, an adequate dietary intake of Se is essential. Hence, the UK department of health advised in 1991 that the desirable average intakes of Se for an adult man and woman are 75 and 60 µg/day, respectively. The Se level in food product depends on its concentration in the soil and it enters the food chain through the plants.

Conclusion: In some parts of the world where Se is not sufficient in the plants, Se-deficiency diseases have been identified such as Keshan disease, an endemic cardiomyopathy with high mortality rates in China. An enrichment of foods with Selenium has greatly reduced the incidence of this disease. Therefore, enrichment of foods with Selenium can be an effective factor to overcome Se deficiency.