of vomiting, nausea, nerve damage, skin rashes, and
brittle bones. Selenium toxicity is rare in the Unites
States with a few reported cases associated with indus-
trial accidents or manufacturing errors leading to an
excessively high dose of selenium in a supplement.
On the other hand, diabetes and arthritis have
been extensively shown to be associated with selenium
deficiency. Gastrointestinal problems, such as Crohn’s
disease, or surgical removal of part of the stomach can
lead to selenium defieciency.
Interactions
Since selenium is part of the selenoproteins enzymes
of the body, it is believed to interact with every nutrient
that affects the antioxidant balance of cells. Selenium as
gluthathione peroxidase also appears to work in con-
junction withvitamin Ein limiting the oxidation of
lipids. Animal oxidative stress studies indicate that sele-
nium can prevent some of the damage resulting from
vitamin E deficiency. Thioredoxin reductase is also
believed to maintain the antioxidant function ofvitamin
C. A selenium deficiency may also worsen the effects of
iodinedeficiency in the thyroid. At present, few inter-
actions between selenium and medications are known.
The anticonvulsant medication, valproic acid, has been
found to decrease plasma selenium levels. Supplemental
sodium selenite has been found to decrease toxicity from
the antibiotic nitrofurantoin and the herbicide paraquat
in animals.
Aftercare
When the diet is corrected for selenium imbalance,
most symptoms tend to disappear on intake to recom-
mended RDA levels. People at risk of selenium deficiency,
due to gastrointestinal disease or severe infection, are
evaluated by physicians for depleted selenium blood levels
to determine the need for supplementation.
Complications
Acute and fatal complications have occurred with
accidental ingestion of gram quantities of selenium.
Significant selenium toxicity was reported in 13 indi-
viduals who took supplements that contained 27,300
mg per tablet due to a manufacturing error. Selenosis
may occur with smaller doses of selenium over long
periods of time. Overall, selenium deficiency is rare in
the United States. When it occurs, it results in a
decrease of the activity of the selenium-dependent
enzymes, especially if the vitamin E is also missing. A
lack ofantioxidantsin the heart, liver and muscles can
lead to tissue death and organ failure. Selenium defi-
ciency has also been suggested as a probable cause of
Keshan’s disease and Kashin-Beck disease and is cur-
rently associated with anemia, cataracts, increased
risk ofcancer, heart disease, stroke , diabetes, arthri-
tis, decreased immune function, early aging, infertility,
miscarriages, and birth defects in women.Parental concernsMaintaining good nutrition in the home includes
keeping informed about the food sources of various
mineralssuch as selenium. A first source of informa-
tion is the Nutrition Fact labels that list them in milli-
grams or micrograms and as a percentage of the RDA.
Parents should also be aware of the risks associated
with both selenium deficiency and over-consumption.Resources
BOOKS
Bogden, J., edClinical Nutrition of the Essential Trace Ele-
ments and Minerals (Nutrition and Health).Totowa,
NJ: Humana Press, 2000.
Challem, J., Brown, L.User’s Guide to Vitamins & Minerals.
Laguna Beach, CA: Basic Health Publications, 2002.
Garrison, R., Somer, E.The Nutrition Desk Reference.New
York, NY: McGraw–Hill, 1998.
Griffith, H. W.Minerals, Supplements & Vitamins: The
Essential Guide.New York, NY: Perseus Books Group,
2000.
Larson Duyff, R.ADA Complete Food and Nutrition Guide,
3rd ed.Chicago, IL: American Dietetic Association,
2006.
Newstrom, H.Nutrients Catalog: Vitamins, Minerals, Amino
Acids, Macronutrients—Beneficials Use, Helpers,
Inhibitors, Food Sources, Intake Recommendations.
Jefferson, NC: McFarland & Company, 1993.
Quesnell, W. R.Minerals : The Essential Link to Health.
Long Island, NY: Skills Unlimited Press, 2000.
Wapnir, R. A.Protein Nutrition and Mineral Absorption.
Boca Raton, FL: CRC Press, 1990.
ORGANIZATIONS
American Dietetic Association (ADA). 120 South Riverside
Plaza, Suite 2000, Chicago, IL 60606-6995. 1-800/877-
1600.<www.eatright.org>.
American Society for Nutrition (ASN). 9650 Rockville
Pike, Bethesda, MD 20814. (301) 634-7050.
<www.nutrition.org>.
Office of Dietary Supplements, National Institutes of
Health. National Institutes of Health, Bethesda,
Maryland 20892 USA.<ods.od.nih.gov>.
U.S. Department of Agriculture, Food and Nutrition
Information Center. National Agricultural Library,
10301 Baltimore Avenue, Room 105, Beltsville, MD- (301) 504-5414.<www.nal.usda.gov>.
Monique Laberge, Ph.D.Selenium