Liquid Selenium
T.
J. Clark Liquid Selenium:
Selenium (Se) is an essential trace element that
functions as a component of enzymes involved in antioxidant protection and
thyroid hormone metabolism. In several intra- and extra-cellular glutathione
peroxidases, iodothyronine 5?-deiodinases, and in thioredoxin reductase,
selenium is located at the active centers as the selenoamino acid,
selenocysteine (SeCYS). At least two other proteins of unknown function also
contain SeCYS. Although SeCYS is an important dietary form, it is not directly
incorporated into these specific selenium-proteins; instead, a co-translational
process yields tRNA-bound SeCYS. In contrast, selenium as seleno-methionine is
incorporated non-specifically into many proteins, as it competes with methionine
in general protein synthesis. Therefore, tissues often contain both specific, as
well as the nonspecific, selenium-containing proteins when both SeCYS and
selenomethionine are consumed, as found in many foods.
IMPORTANCE: A major antioxidant nutrient, protects cell membranes and prevents
free radical generation thereby decreasing the risk of cancer and disease of the
heart and blood vessels. Medical surveys show that increased selenium intake
decreases the risk of breast, colon, lung and prostate cancer. Selenium also
preserves tissue elasticity; slows down the aging and hardening of tissues
through oxidation; helps in the treatment and prevention of dandruff.
Deficiencies: Selenium deprivation reduces activities of the selenium-dependent
enzymes. The signs in animals depend upon vitamin E status and appear only when
both nutrients are limiting. They vary according to species. For example,
selenium- and vitamin E-deficient animals show myopathies of skeletal (e.g.,
sheep, cow, horse), cardiac (pig) or smooth (dog, cow) muscle; hepatic necrosis
(rat, pig); increased capillary permeability (chicken); or pancreatic acinar
degeneration (chicken). Characteristic signs of selenium deficiency have not
been described in humans, but very low selenium status is a factor in the
etiologies of a juvenile cardiomyopathy (Keshan Disease) and a chondrodystrophy
(Kashin-Beck Disease) that occur in selenium-deficient regions of China. May
result in premature aging, heart disease, dandruff, loose skin.
Diet recommendations: The Recommended Dietary Allowances are in µg/day: 0-0.5
yrs, 10; 0.5-1.0 yrs, 15; 1-6 yrs, 20; 7-10 yrs, 30; males 11-14 yrs, 40;
females 11-14 yrs, 45; males and females 15-18 yrs, 50; adult males, 70; adult
females, 55; pregnancy, 65; and lactation, 75.
Food sources: The most important sources in
American diets are meats, fish and grains. Brazil nuts can have relatively high
selenium concentrations. Foods of low protein content, including most fruits and
vegetables, provide little selenium. Food selenium is absorbed with efficiencies
of 60-80%; the greatest factor affecting the utilization of food selenium is its
chemical form.
Toxicity: Selenium toxicity is characterized by
dermatologic lesions; selenotic animals and humans develop brittle hair and
nails/hooves. Sporadic cases of selenium-poisoning have been reported involving
industrial or accidental exposures to selenium-compounds. In certain rural
Chinese communities chronic intakes of very high amounts (several milligrams per
day) of selenium were linked to skin, hair and nail abnormalities which
disappeared upon resuming regular selenium intakes. Selenium has been identified
as the cause of birth deformities in migratory wildfowl in a wetland area
(Kesterson Reservoir, CA) which receives selenium-enriched irrigation
wastewater. This case involved the biological amplification of selenium by
aquatic plants which were important in the diet of affected animals. The
Reference Dose (RfD) set by the Environmental Protection Agency is 5 µg/kg body
weight/day or 350 µg/day for a 70 kg individual. This intake is regarded as
having no significant risk of a deleterious effect over a lifetime of exposure.
Recent research: Preliminary findings suggest that selenium may have an
anticancer effect in humans. Animal studies indicate that selenium deficiency
may decrease the resistance of the host to infection with certain viruses.
Supplement Facts
Serving Size: 1 Teaspoon (5ml)
Serving Per Container: 47 |
|
Amount
per serving |
% USRDA |
Calories |
4 |
<2 |
Total Carbohydrate |
1 g |
<2 |
Total Fat |
0 g |
0 |
Sodium |
0 g |
0 |
Selenium (l-Selenomethionine) |
70 mcg |
100 |
Phytogenic Mineral Catalyst |
100 mcg |
** |
Calcium, Chloride, Cobalt, Chromium, Magnesium,
Boron, Manganese, Molybdenum, Selenium, Iron, Copper, Phosphorus,
Sulfur, Potassium, Iodine and Zinc |
* Percent Daily Values based on a 2,000 calorie
diet
** No daily value established |
Directions: Take 5 ml once daily with food |
* This statements have not been
evaluated by the Food and Drag Administration.
This products are not intended
to diagnose, treat, cure or prevent any disease. |
Beck, M. A. & Levander, O. A. (1998) Dietary oxidative stress and the potentiation of viral infection. Ann. Rev. Nutr. 18: 93-116.
Combs, G. F., Jr. & Gray, W. P. (1998) Chemopreventive agents:
selenium. Pharmacol. Expt. Therapeut.
79: 179-192.
Xia, Y. M., ed. (1997) Proceedings of Selected Papers of the Sixth
International Symposium on Selenium in
Biology and Medicine. Biomed. Environ. Sci. 10: 113-368.
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