Blood selenium levels of Indians: Delhi area

Selenium levels in whole blood - The borderline low analysis

OBJECTIVES

Selenium is a very important micronutrient. Food is the major source for selenium uptake and the average blood levels is seen to be highly affected by dietary habits as selenium levels in food naturally depend on the kind of soil they are grown upon and in processed foods its levels depend on fortification. Deficiency of this vital nutriment needs to be assessed to understand deficiency prevalence.

DESIGN AND METHODS

A total number of 529,461 subjects were tested for their blood selenium levels. The study cohort consisted of 284,189 males and 245,272 females respectively. Average blood selenium levels have been analyzed across both the genders using the analytical platform of Inductively Coupled Plasma - Mass Spectrometry.

RESULTS

For borderline low analysis of selenium, values of </= 105 μg/L were considered. The total frequency of borderline low recorded in our study was 3.7%. The average blood selenium levels and further geographical highlights have been included and discussed.

CONCLUSION

Our report is an effort to create awareness about the less discussed micronutrient necessity to be tested in the Indian scenario.

Blood selenium status in normal Punjabi population of Pakistan

Selenium concentrations in the blood of 112 (56 females and 56 males) normal subjects, from different regions of the Punjab (Pakistan), have been determined using the technique of inductively coupled plasma-mass spectrometry. The whole blood selenium concentrations were found to be 452 ± 12 ppb (parts per billion or nano-gram of Se per gram freeze-dried blood or 96 ± 3 μg/L ), with 470 ± 16 ppb (or 100 ± 4 μg/L) in female and 435 ± 16 ppb (or 92 ± 4 μg/L) in male population. Compared with other populations of the world [corrected] these levels are similar with the exception of the low-selenium-region of China. [corrected].

Selenium in global food systems

Food systems need to produce enough of the essential trace element Se to provide regular adult intakes of at least 40 μg/d to support the maximal expression of the Se enzymes, and perhaps as much as 300 μg/d to reduce risks of cancer. Deprivation of Se is associated with impairments in antioxidant protection, redox regulation and energy production as consequences of suboptimal expression of one or more of the Se-containing enzymes. These impairments may not cause deficiency signs in the classical sense, but instead contribute to health problems caused by physiological and environmental oxidative stresses and infections. At the same time, supranutritional intakes of Se, i.e. intakes greater than those required for selenocysteine enzyme expression, appear to reduce cancer risk. The lower, nutritional, level is greater than the typical intakes of many people in several parts of the world, and few populations have intakes approaching the latter, supranutritional, level. Accordingly, low Se status is likely to contribute to morbidity and mortality due to infectious as well as chronic diseases, and increasing Se intakes in all parts of the world can be expected to reduce cancer rates.