Download Selenium - Medical Nutrition Therapy Manual

Hannah Smith
KNH 413
April 8, 2012
Medical Nutrition Therapy Nutrient: Selenium
What is the nutrient?
The nutrient is selenium. It is necessary for vital immune system function. It works in conjunction with
vitamin E, C, and B3 as an antioxidant to prevent free radical damage in the body
(http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/10-foods-rich-in-selenium.html).
What is the RDA/DRI for the nutrient?
The RDA for selenium is:
 Children (under 3): 20 mcg
 Children (48): 30 mcg
 Children (9-13): 40 mcg
 Adolescents (14-18): 55 mcg
 Adults 19 and older: 55 mcg
 Pregnant women: 60 mcg
 Lactating women: 70 mcg
Reference: http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/10-foods-rich-in-selenium.html
The DRI for selenium is:
 1 - 3 years: 17 μg/d
 4 - 8 years: μg/d
 9 - 13 years (male and female): 35 μg/d
 14 - >70 years (male and female): 45 μg/d
 Pregnant women: 49 μg/d
 Lactating women: 59 μg/d
Reference:
http://www.iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrition/DRIs/5_Sum
mary%20Table%20Tables%201-4.pdf
How is the nutrient metabolized?
Selenium is mainly absorbed through various sites throughout the duodenum. Many forms of this
element are well absorbed. The usual forms absorbed are part of amino acids within proteins. The exact
mechanisms of selenium transport are unclear and very debatable in the science and nutrition worlds. It is
hypothesized that selenium enters red blood cells through diffusion and carried throughout the body. Within the
blood, free selenium binds to lipoproteins. The selenium that is absorbed becomes a part of transport and
storage proteins. The heart, kidney, lung, liver, pancreas, and muscle store high amounts of selenium. The
balance of selenium in the body is mainly regulated through excretion. If too much selenium is consumed then
it is excreted by the lungs, causing a garlic smell or odor
(http://www.exrx.net/Nutrition/Antioxidants/Selenium.html#anchor3688468).
What are food sources of the nutrient?
Food sources of the nutrients include: Brazil nuts, sunflower seeds, fish (especially tuna, halibut,
sardines, flounder, salmon), shellfish (especially oysters, mussels, shrimp, clams, scallops), meat (especially
beef, liver, lamb, pork), poultry (especially chicken and turkey), eggs, mushrooms (especially button, crimini,
shiitake), grains (especially wheat germ, barley, brown rice, oats), and onions.
Reference: http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/10-foods-rich-in-selenium.html
What disease states alter the nutrients metabolism?
Some diseases associated with low levels of selenium include: HIV and Crohn’s disease
(http://www.healthtestingcenters.com/selenium.aspx).
What are the tests or procedures to assess the nutrient level in the body?
One test done to assess selenium levels is the selenium deficiency test. People with nutritional
absorption disorders are usually required to undergo a variety of nutritional deficiency tests, including one for
selenium. These tests are typically done by doing a simple blood test and blood analysis to determine the levels
of each nutrient, in the blood (http://www.testcountry.org/selenium-deficiency-test.htm).
What is the drug –nutrient interactions?
The absorption of selenium is enhanced using vitamin A, C, E, and reduced glutathione. On the other
hand, the absorption of selenium is reduced by heavy metals, like mercury
(http://www.exrx.net/Nutrition/Antioxidants/Selenium.html#anchor3688468). Some drugs that lower selenium
levels in the body include: Cisplatin, clozapine, corticosteroids, valproic acid. When taken with Clopidogrel,
Warfarin, Heparin, and Aspirin, selenium may increase risk of bleeding. Selenium seems to make the sedative
effects of Butabarbital, Mephabarbital, Phenobarbital, and Secobarbital last longer
(http://www.umm.edu/altmed/articles/selenium-000325.htm).
How is the nutrient measured?
Selenium is measured in micrograms based on the Selenium RDA, DRI, and Upper Tolerable Limits
recommendations
(http://www.iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrition/DRIs/5_Su
mmary%20Table%20Tables%201-4.pdf).
What is the Upper Tolerable Limits?
The upper tolerable limits of selenium are:
 0-6 months: 45 mcg/day
 7-12 months: 60 mcg/day
 1-3 years: 90 mcg/day
 4-8 years: 150 mcg/day
 9-13 years: 280 mcg/day
 14-18 years: 400 mcg/day
 19 + years: 400 mcg/day
Reference: http://ods.od.nih.gov/factsheets/selenium-HealthProfessional/
What are the physical signs of deficiency?
Deficiency of selenium is rare and usually only occurs in areas where soil concentration of selenium is
low. The physical signs of deficiency include:
 Autoimmune problems (psoriasis or thyroid disease)
 Stomach, throat, prostate cancers
 Some mood disorders
Reference: http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/10-foods-rich-in-selenium.html
 Can make body susceptible to other illnesses
Reference: http://ods.od.nih.gov/factsheets/selenium-HealthProfessional/
What are physical signs of toxicity?
The physical signs of selenium toxicity include:
 Hair loss
 White spots on fingernails
 Fatigue, dizziness
 Nausea
Reference: http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/10-foods-rich-in-selenium.html