Selenium exposure by food sources. impact into human health due selenium deficiency as well as selenium excess

Selenium is important micronutrient with great impact into human health. In mammal metabolism it is included as coenzyme in several key enzymes. There are 35 selenoproteins identified, which role is not fully clarified yet. Selenium is well known both with its high toxicity and presence of several important diseases impacted by its deficiency. Selenium dosage is also a problem. Minimal daily required dose differs less than an order from maximum allowed daily intake. Northern Balkans is territory known with highest selenium deficiency problem in Europe. Also in Bulgarian territory there are significant regional variations in diet. Those facts, as well as presence of major consumers of selenium accumulating foods, are preconditions not only for concerns about selenium deficiency, but also for health effect from selenium over dosage