| Selenium and Thyroid Regulation Selenocysteine is necessary for the maximal enzyme activity and the conversion
of T4 to T3 for thyroid regulation. This explains why conversion of T4
to T3 is impaired in experimental selenium deficiency and identifies an
essential role for selenium in thyroid hormone action.
Berry M, et al., "Type 1 iodothyronine deiodinase is a
selenocysteine-containing enzyme," Nature, January 1991;349: 438-440.
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Heart Disease and Its Association to Selenium An inverse correlation between the plasma selenium and the severity of
coronary atherosclerosis was observed in 91 hospitalized patients who
were being examined for clinical evaluation of chest pain.
Moore JA, et al., "Selenium concentrations in plasma of
patients with arteriographically defined coronary atherosclerosis," Clinical
Chemistry, 1984; Vol. 30, No. 7: 1171-1173.
In a 7-year follow up study of 11,000 middle-aged people, those who had
low concentrations of serum selenium (less than 45 mcg/l) at the start
of the survey had an excess risk of coronary and cardiovascular death
and myocardial infarction.
Solonen JT, et al., "Association between cardiovascular
death and myocardial infarction and serum selenium in a matched-pair longitudinal
study," The Lancet, July 24, 1982: 175-179.
The association between serum selenium concentration and five-year risk
of cardiovascular disease was studied in 1,220 men aged 55 to 74 years.
All cause and cardiovascular deaths were associated significantly with
serum selenium of less than 45 mcg/l.
Virtamo J, et al., "Serum selenium and the risk of coronary
heart disease and stroke," American Journal of Epidemiology, Vol. 122,
No. 2: 276-282.
Comparing 84 patients with acute myocardial infarction (cases) to 84
population controls, all selenium measurements were lower in the cases
than in controls.
Kok FJ; et al., "Decreased selenium levels in acute myocardial
infarction", The Journal of the American Medical Association, February
24, 1989; Vol. 261, No. 8: 1161-1164.
back to top Selenium and Bioavailability
Supplying 200 mcg/day of supplemental selenium to breast-feeding women
as selenomethionine or selenium yeast resulted in a significant increase
in plasma selenium in their breast-feeding infants.
McGuire MK, et al., "Selenium status of infants is influenced
by supplementation of formula or maternal diets," American Journal of
Clinical Nutrition, 1993;58: 643-648.
Lactating mothers supplied 200mcg/day of selenium yeast show more selenium
activity in the body than mothers taking 200 mcg/day of sodium selenite.
Trafikowska U, et al. "Organic and inorganic supplementation
to lactating mothers increase the blood and milk Se concentrations and
Se intake by breast-fed infants," Journal of Trace Element Med Biol, July
1998; 12(2): 77-85.
Plasma selenium concentrations increased by approximately 67% in the
group of patients receiving 200 mcg/day of selenium yeast compared to
the placebo yeast group.
Clark LC, et al., "Effects of selenium supplementation
for cancer prevention in patients with carcinoma of the skin," The Journal
of the American Medical Association, December 25, 1996; Vol. 276, No.
24: 1957-1963.
To determine the possibility of improving the selenium status of exclusively
breast-fed infants, 200 mothers received either placebo, 100 mcg of selenite,
or 100 mcg of yeast Se daily. Yeast-Se in this dose was safe and more
effective than selenite in increasing the Se concentrations of maternal
serum and milk, and infant serum.
Kumpulainen, J., et al., "Selenium status of exclusively
breast-fed infants as influenced by maternal organic or inorganic selenium
supplementation," The American Journal of Clinical Nutrition, November
1985;42: 829-835.
This study shows that different forms of selenium occupy different metabolic
pools in the body. Although Selenium from wheat and yeast was clearly
available for glutathione peroxidase synthesis, presumably some of this
selenium was deposited in the tissues in a form that could be mobilized
or recycled later once the dietary supplementation was withdrawn.
Levander O, et al., "Bioavailability of selenium to Finnish
men as assessed by platelet glutathione peroxidase activity and other
blood parameters," The American Journal of Clinical Nutrition, June1983;
887-897.
back to top H I V HIV Patients receiving oral selenium treatments show increased values
of selenodependent glutathione peroxidase compared to those receiving
a placebo or beta-carotene.
Delmas-Beauvieux. M; etal. "The enzymatic antioxidant
system in blood and glutathione status in human immunodeficiency virus
(HIV) infected patients: effects of supplementation with selenium or
beta-carotene." The American Journal of Clinical Nutrition, 1996; 64:
101-107.
In a Natural Institute of Health funded study of 125 HIV infected men
and women, researchers found that HIV-1 infected patients with a selenium
deficiency, were 19.9 times more likely to die of HIV related causes than
those with adequate selenium levels.
Baum MK, et al., Journal of Aids, September 30, 1997.
back to top Male Sperm Motility
The sperm capsule selenoprotein is a structural selenoprotein found in
the midpiece region of the sperm tail. In selenium deficiency, morphological
anomalies in this region give rise to spermatozoa with impaired motility.
Behne,D; et al. "Efficiency of selenium deficiency on
testicular morphology and function in rats," Journal Reproduction Fertility,
1996; 106: 291-297.
In a 3-month trail of 69 patients with reduced motility, selenium treatment
significantly (P=O.002) increased plasma selenium concentrations and sperm
motility (P=0.023). Selenium supplementation in subfertile men with low
selenium status can improve sperm motility and the chance of successful
conception.
MacPherson, SR; et al. "The effect of oral selenium supplementation
on human sperm motility," British Journal of Urology, July 1998; 82(1):
76-80.
back to top General Selenium and more efficiently Selenium + Vitamin E supplementation, in
experimental diabetes could play a role in controlling oxidative status
and altered lipid metabolism in liver, thereby maintaining favorable fatty
acid distribution in the major tissues effected by diabetic complications.
Douillet C, et al., "Effect of selenium and vitamin E
supplements on tissue lipids, peroxides, and fatty acid distribution in
experimental diabetes," Lipids, April 1998; 33(4): 393-399.
A 4ppm selenium supplement to the drinking water was provided before,
during, and after 20 weekly injections of 20mg DMH (Dimethylhydrazine)
per kg body weight. The incidences of colon tumors in groups provided
selenium before DMH, before and during DMH, and only during DMH treatment
were reduced to 39,43,and 36% respectively.
Jacobs.M.N. et al., "Biochemical and clinical effects
of selenium on Dimethylhydrazine induced colon cancer in rats", Cancer
Research, November 1981; 41: 4458-4465.
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