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The Eclectic Physician
Vitamin and Mineral Information
Selenium
The information on this page compiled by
Beth Burch N.D.
Index
(click on the keywords)
Function
Selenium is a vital part of the enzyme glutathione
peroxidase, which works with vitamin E as an antioxidant to protect cells
from free radical damage. Selenium is also important in the activation
of thyroid hormone and helps to decrease heavy metals like lead, mercury,
cadmium and aluminum. Mild deficiency of selenium results in decreased
immune function and and increased risk of cancer. More pronounced deficiency
causes Keshan disease, a severe heart disease of children and young women.
Selenium deficiency has also been linked to Kashin-Beck disease, an arthritic
condition and to heart disturbances and muscle weakness. Deficiency occurs
with malnutrition and in areas where the soil has very low selenium levels.
Selenium toxicity can occur with intake of as little as 900 mcg daily and
is characterized by depression, nervousness, irritability, nausea, vomiting,
skin rash, garlic smelling breath and hair and fingernail loss.
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Forms
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Food Sources
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Wheat germ, brazil nuts and nutritional yeast are all high in selenium.
Whole grains and seafood are good sources. Selenium content of foods depends
on the level of selenium in the soil.
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Dosage
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Recommended Daily Allowance (RDA)
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Infants- 10-15 mcg
-
Children (ages 1-10)- 20-30 mcg
-
Adults- 40-70 mcg
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Pregnancy- 65 mcg
-
Lactation- 75 mcg
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Optimal Supplementation
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50-200 mcg or 1.5 mcg per pound of body weight daily
Treatment
of Health Conditions
Conditions used
for
-
Prevention of cancer (1, 2, 3,
4, 5)
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Prevention of heart disease and high blood pressure (6)
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Immune system enhancement (7,
8, 9)
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Respiratory syncytial virus (10)
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Selenium deficiency
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Side effects
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Toxic at doses above 900 mcg daily resulting in depression, nervousness,
irritability, nausea, vomiting, skin rash, garlic smelling breath and hair
and fingernail loss.
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Contraindications
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Interactions
with other nutrients
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Selenium increases the antioxidant activity of vitamin E
-
Vitamin C and zinc may decrease absorption of selenium
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Interactions
with medications and herbs
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Chemotherapy medications may increase requirements for selenium
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References
1. Ganther HE, Selenium metabolism, selenoproteins and mechanisms
of cancer prevention: complexities with thioredoxin reductase, Carcinogenesis
1999;20(9):1657-66
2. Nelson MA et al, Selenium and prostate cancer prevention, Semin
Urol Oncol 1999;17(2):91-6
3. Knekt P et al, Is low selenium status a risk factor for lung cancer?,
Am J Epidemiol 1998;148(10):975-82
4. Ujiie S et al, Serum selenium contents and the risk of cancer, Gan
To Kagaku Ryoho 1998;25(12):1891-7
5. Combs GF Jr et al, Chemopreventive agents: selenium, Pharmacol Ther
1998;79(3):179-92
6. Mihailovic MB et al, Blood and plasma selenium levels and GSH-Px
activities in patients with arterial hypertension and chronic heart disease,
J Environ Pathol Toxicol Oncol 1998;17(3-4):285-9
7. Girodon F et al, Impact of trace elements and vitamin supplementation
on immunity and
infections in institutionalized elderly patients: a randomized controlled
trial. MIN. VIT. AOX. geriatric network, Arch Intern Med 1999;159(7):748-54
8. Ilback NG et al, Effects of selenium supplementation on virus-induced
inflammatory heart disease, Biol Trace Elem Res 1998;63(1):51-66
9. Sun E et al, The mechanism for the effect of selenium supplementation
on immunity, Biol Trace Elem Res 1995;48(3):231-8
10. Liu X et al, Effects of selenium supplement on acute lower respiratory
tract infection caused by respiratory syncytial virus, Chung Hua Yu Fang
I Hsueh Tsa Chih 1997;31(6):358-61
11.
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* The information presented in this web site is intended to inform and educate.
It is not intended replace a qualified medical practitioner to diagnose or treat medical conditions.
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