- Selenium deficiency
Selenium deficiency is relatively rare in healthy well-nourished individuals. It can occur in patients with severely compromised intestinal function, those undergoing
total parenteral nutrition , and also [ [http://www.ajcn.org/cgi/content/full/71/2/590 Effect of micronutrient status on natural killer cell immune function in healthy free-living subjects aged >=90 y1 - Ravaglia et al. 71 (2): 590 - American Journal of Clinical... ] ] on advanced aged people (over 90). Alternatively, people dependent on food grown from selenium-deficient soil are also at risk. In the USA, theDietary Reference Intake for adults is 55 µg/day. In the UK it is 75 µg/day for adult males and 60 µg/day for adult females. 55 µg/day recommendation is based on full expression of plasmaglutathione peroxidase .Selenoprotein P cite journal |author=Papp LV, Lu J, Holmgren A, Khanna KK |title=From selenium to selenoproteins: synthesis, identity, and their role in human health |journal=Antioxid. Redox Signal. |volume=9 |issue=7 |pages=775–806 |year=2007 |pmid=17508906 |doi=10.1089/ars.2007.1528] is a better indicator of selenium nutritional status, and full expression of it would require more than 66 µg/day.cite journal |author=Xia Y, Hill KE, Byrne DW, Xu J, Burk RF |title=Effectiveness of selenium supplements in a low-selenium area of China |journal=Am. J. Clin. Nutr. |volume=81 |issue=4 |pages=829–34 |year=2005 |pmid=15817859 |doi=]Presentation
Selenium deficiency can lead to
Keshan disease , which is potentially fatal. Selenium deficiency also contributes (along withiodine deficiency ) toKashin-Beck disease . [http://www.atsdr.cdc.gov/toxprofiles/tp92-c3.pdf DRAFT ] ] The primary symptom of Keshan disease is myocardialnecrosis , leading to weakening of the heart. Kashin-Beck disease results inatrophy , degeneration andnecrosis ofcartilage tissue. [ [http://content.nejm.org/cgi/content/short/339/16/1112 NEJM - Kashin-Beck Osteoarthropathy in Rural Tibet in Relation to Selenium and Iodine Status ] ] Keshan disease also makes the body more susceptible to illness caused by other nutritional, biochemical, or infectious diseases.Selenium is also necessary for the conversion of the thyroid hormone
thyroxine (T4) into its more active counterpart,triiodothyronine , and as such a deficiency can cause symptoms ofhypothyroidism , including extreme fatigue, mental slowing,goitre ,cretinism and recurrent miscarriage.Epidemiology and prevention
These diseases are most common in certain parts of China where the soil is extremely deficient in selenium. Studies in
Jiangsu Province of China have indicated a reduction in the prevalence of these diseases by taking selenium supplements.References
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