Background: Disorders in the human body due to selenium defi ciency are associated with geographiclocation or environment, especially selenium concentrations in water and in soil. Selenium concentrationsin the blood of populations around the world, varies greatly. To date, no research has been conducted onaverage serum selenium level of adult Mongolians.Goal. To conduct a comparative study on the average serum selenium level of adult Mongolians bygeographic regions.Materials and Methods. In this study were participated 2339 healthy subjects randomly selectedfrom sampling units based on 4 geographical regions of Mongolia. For the study were used thequestionnaire and biochemical methods. Blood samples were collected from all subjects and serumselenium concentration was measured by the thermo fi sher scientifi c analyzer using atomic absorptionspectrophotometer method.Result: The mean serum selenium level in adult Mongolians was 0.78 μmol/l. A comparative analysisshowed a statistically signifi cant difference (ð<0.0001) in the mean serum selenium level of adultMongolians living in different geographic regions. In particular, the mean serum selenium level ofadult Mongolians was 0.85 μmol/l in the Altai Mountain, 0.57 μmol/l in Khangai mountain, 1.0 μmol/l inGobi, 0.71 μmol/l in Dornod steppe regions and thus indicator was 0.75 μmol/l among adult citizens ofUlaanbaatar. Majority of residents living in Khangai mountain and Dornod steppe regions were at a riskof selenium defi ciency.Conclusions:1. Comparative analysis of the average serum selenium level of adult Mongolians by region showedthat the Gobi region has highest (1.0 μìîë/ë) and Khangai region has the lowest (0.57 μìîë/ë).2. Study fi ndings showed that 7 – 8 individuals out of 10 residents of Dornod steppe and Khangairegions were at the risk of selenium defi ciency.

IntroductionThe trace elements selenium is a constituent of the antioxidant enzyme glutathione peroxidase. Becauseit boosts the body’s antioxidant capacity, selenium is thought to have some ability to control cell damagethat may lead to cancer. Selenium low status has been linked to increased risk of various diseases, suchas cancer and heart disease.GoalInvestigate serum selenium level of adult mongolians and conduct age and gender coparartive analysisof the serum selenium content.Materials and MethodsCross sectional study was performed among the 2339 apparently healthy Mongolians of both gendersaged ≥18 years. In the study were used questionnaire and biochemical methods. Blood samples werecollected from all subjects and serum selenium concentration was measured by atomic absorptionspectrophotometry method using thermo fisher scientific analyzer.ResultsThe mean and confidence interval of serum selenium level in adult Mongolians was 0.78 μmol/l (95%CI0.77-0.79) and there was no significant difference between genders. Thus the mean was 0.77 μmol/l(95%CI 0.76-0.80) among women and in men it was 0.78 μmol/l (95%CI 0.76-0.80). Data analysisrevealed that older age group individuals were at risk of lowered serum selenium level. In particular,the oldest age group of over 60 years (females: 0.74 μmol/l, 95%CI 0.70-0.77; males: 0.68 μmol/l,95%CI 0.64-0.71). The difference in selenium status between age groups was statistically significant inboth sexes. The overall prevalence of serum selenium concentrations indicative risk of deficiency was59.7%, with no significant differences in the prevalence by genders. Survey findings revealed that riskof selenium deficiency had statistically significant difference between age groups among the surveyedmen.Conclusion: The mean value of serum selenium in adult Mongolians was 0.78 μmol/l and there was nosignificant difference between genders.