Selenium

Selenium is an essential trace element and a vital constituent of antioxidant enzymes that participate in various physiological activities and protects the cell against the deleterious effects of free radicals by modulating the cell response. The role of selenium has been explored in normal thyroid functioning, enhancing immune function, carcinogenesis, cardiovascular diseases, in the prevention of pre-eclampsia, diabetes mellitus and male reproduction etc.

It has been reported that obese people have lower serum selenium levels [23]. The actual incidence of selenium deficiency after bariatric surgery is not well documented, hence it’s difficult to get a clear picture of its deficiency state but post bariatric patients can be at a risk of selenium deficiency secondary to reduction in nutrient intake and altered absorption as selenium is mainly absorbed in the duodenum.

Selenium is assimilated more effectively from plant food than animal products but some dietary constituents (vitamin C and vitamin E) generally affect its absorption. Also, other factors like, copper, magnesium, zinc, vitamin B, lipoic acid and some amino acids such as cysteine, glutamine, and methionine may play a role that affect the level of selenium.

A recent study following bariatric surgery showed that even with multivitamin and mineral supplements, a reduction in selenium concentration was noted in the early post-operative period which normalised during the first year after surgery [24].

Selenium deficiency is uncommon, but severe deficiency can cause symptoms and diseases including myopathy, cardiomyopathy, arrhythmia, muscle wasting, impaired immunity, low thyroid function, loss of skin and hair pigmentation, whitened nail beds, and progressive encephalopathy. There is an indication that selenium deficiency may contribute to the progression of viral infections.

Plasma erythrocyte and whole blood selenium, plasma selenoproteins P, and plasma platelet and whole blood glutathione activity are good biomarkers of selenium status in the body. In humans the selenoenzyme methionine sulfoxide reductase B1 (MsrBl) is the most sensitive protein marker of selenium status [25].

The recommended Dietary Allowance for Selenium

Selenium

Males

Females

RDA* (India) [16]

40 mcg

40 mcg

RDA*(US) [17]

55 mcg

55 mcg

RNI**(UK) [18]

75 mcg

60 mcg

NRV***(Australia,Newzealand) [19]

70 mcg

60 mcg

 
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