Selenium

Selenium is an essential mineral which works closely with vitamin E. Toxicity is more of a problem with selenium than most nutrients, and doses over 800 to 1000mcg should be used with caution or under a doctor’s supervision only. The National Academy of Sciences’ Food and Nutrition Board has stated that a daily intake of between 50 to 300 micrograms of selenium is “safe and adequate”. Therapeutic doses often range from 200 to 400mcg daily. Selenium is absorbed fairly easily in the upper portion of the GI tract.

Organic and inorganic forms of selenium may have different properties. Organic forms include selenomethionine, selenocysteine, amino acid chelates, yeast, and kelp-bound selenium. Inorganic forms include sodium selenite and sodium selenate. Incrementally increasing doses of sodium selenite are being used for decreasing sensitivity to environmental toxins. Your naturopath should be familiar with this protocol.

Selenium is naturally found in foods high in protein, such as fish, meat, poultry, cereals, seeds and other grains. It can also be found in vegetables like garlic, mushrooms and asparagus. Brazil nuts, especially with their shells on, are very high in selenium. Some experts believe that vegetarians may not be getting enough selenium unless supplemented.

Natural selenium levels in the soil are highly variable throughout the world. In the U.S., the Eastern Coastal Plain and the Pacific Northwest have the lowest selenium levels and people in these regions naturally ingest about 60 to 90mcg per day. This compares to a range of 60 to 200mcg across the U.S. with 125mcg being average.

A study was conducted in the above region. People in this study were given either a placebo or selenium supplements of 200mcg (three times their normal intake) which were made up of selenium enriched yeast, an organic form of selenium as distinguished from most other supplements that are inorganic and may not have the same effect. While the study did not prove what it originally set out to, namely that selenium reduces the risk of skin cancer, it did find that it greatly reduced the risk of many other kinds of cancer. People taking the selenium supplements had 71% fewer prostate cancers, 67% fewer esophageal cancers, 62% fewer colorectal cancers and 46% fewer lung cancers than the people who were taking the placebos.

 


Selenium can help with the following

Aging  


Autoimmune  

Chronic Thyroiditis

Three months of supplementation with 200mcg selenium daily reduced thyroid peroxidase antibodies (TPOAb) but had no effect on Tg antibodies (TgAb) in a well-controlled study of 70 women with autoimmune thyroiditis. TPOAb and/or TgAb levels were above 350 IU/ml. [ J Clin Endocrinol Metab 2002;87(4): pp.1687-1691]



 

Hyperthyroidism

On June 22, 2001 Dr. Barbara Gasnier reported the findings at the 83rd Annual Meeting of the Endocrine Society in Denver, Colorado that selenium supplementation may prevent progression of autoimmune thyroid disease, especially during the onset of the disease.

According to the researchers, selenium deficiency appears to contribute to the development and maintenance of autoimmune thyroiditis because of its effect on the function of selenium-dependent enzymes, which can modulate the immune system.

Selenium supplementation with 200mcg of sodium selenite may improve the inflammatory activity seen in patients with autoimmune thyroiditis, but whether this effect is specific for autoimmune thyroiditis or may also be effective in other organ-specific autoimmune diseases remains to be investigated. Selenium supplementation may lower free radical activity, which contributes to inflammation.

It appears that taking selenium without iodine will result in a decrease in production of Thyroxine (T4), although there may be an initial transient increase in T4 to T3 conversion and hence higher T3 and seemingly worse hyperthyroidism.



Circulation  

Atherosclerosis

Dosage: 200mcg per day.



Drug Side Effects  

Radiation, Side-Effects

A review concluded that selenium enhances the benefits of physical therapy in patients with radiation-induced lymphedema. [J Support Oncol 2003;1(2): pp.121­38]



Environment / Toxicity  

Mercury Toxicity / Amalgam Illness

Selenium is able to combine with metals such as cadmium and mercury to reduce their toxicity.



 

Heavy Metal Toxicity

Selenium is able to combine with metals such as cadmium and mercury to reduce their toxicity.



 

Cigarette Smoke Damage

An Italian study of men who smoked found that heavy smokers had lower levels of selenium than lighter smokers and non-smokers. [Atherosclerosis, 1991;87: pp.129-134]



Hormones  

Hypothyroidism

Selenium and iodine are two minerals which are important in the proper functioning of the thyroid. While the importance of iodine has been known for a long time, the importance of selenium has only been discovered and explored since 1990.

The following is a summary of the possible interactions of selenium and iodine to consider when dealing with thyroid abnormalities:



The Immune System  


Infections  


 


 


 


Lab Values  


Metabolic  


Musculo-Skeletal  


 

Rheumatoid Arthritis

Selenium levels are generally low in patients with rheumatoid arthritis. Low selenium levels in joint tissues may be a significant factor contributing to the inflammatory process in rheumatoid arthritis. Selenium plays an important role as an antioxidant and serves as the mineral cofactor in the free-radical scavenging enzyme glutathione peroxidase. This enzyme is also important in reducing the production of inflammatory compounds that cause much of the damage to tissues seen in rheumatoid arthritis. A deficiency of selenium would result in even more significant damage.



Nutrients  


Organ Health  

Hepatitis

Optimal selenium status should be ensured for both prevention and treatment: 200mcg per day is needed to keep your liver healthy. When the micronutrient selenium was added to the diet of 20, 847 people in a Chinese town, the number who became infected with hepatitis B virus was 50% less than for villagers not receiving dietary selenium. Supplementation also markedly reduced the risk of liver cancer among HBV sufferers.

“Selenium also appears to be protective in individuals infected with hepatitis virus (B or C) against the progression of the condition to liver cancer.” [Rayman MP. The importance of selenium to human health. The Lancet. July 15, 2000; volume 356, pp.233-241]



 

Macular Degeneration

Selenium is sometimes recommended, but you should always consult your physician to determine appropriate dosages.



Respiratory  

Asthma

People with low levels of selenium have a high risk of asthma. [Clin Sci 1989;77: pp.495-500] Asthma involves free-radical damage [N Engl J Med 1991;325: pp.586-7 (letter)] that selenium might protect against. In a small double-blind trial, supplementation with 100mcg of sodium selenite (a form of selenium) per day for 14 weeks resulted in clinical improvement in six of eleven patients, compared with only one of ten in the placebo group. [Allergy 1993;48: pp.30-6] Most doctors recommend 200mcg per day for adults (and proportionately less for children) – a higher, though still safe, level.



Risks  

Cancer / Risk - General Measures

Selenium is useful in the prevention of several cancers. As deficient selenium levels are associated with an increased risk of cancers in general, ensuring adequate selenium intake and maximizing selenium status in the presence of an elevated cancer risk is highly recommended.



 

Increased Risk of Lung Cancer

A double-blind study demonstrated that supplementation with 200 mcg/day of selenium (in the form of high-selenium brewer’s yeast) reduced the incidence of prostate, colorectal and lung cancer, and reduced overall cancer mortality by 50%. [JAMA 1996;276: pp.1957-1963]

However, another study found that selenium supplementation was not associated with the incidence of lung and colorectal cancers. [Cancer Epidemiol Biomarkers Prev 2002;11(7): pp.630-639]



 

Increased Risk of Leukemia

In evaluating 59 patients with lymphoid malignancies, such as Hodgkin’s disease, non-Hodgkin’s lymphoma, multiple myeloma and chronic lymphocytic leukemia, serum selenium concentrations were significantly lower in patients than in controls. Clinical stage was inversely associated with selenium levels.



 

Increased Risk of Lymphoma

In evaluating 59 patients with lymphoid malignancies such as Hodgkin’s disease, non-Hodgkin’s lymphoma, multiple myeloma and chronic lymphocytic leukemia, it was found that serum selenium concentrations were significantly lower in patients than in controls. The lower the selenium levels were, the worse the cancer turned out to be.

As deficient selenium levels are associated with an increased risk of cancers in general, ensuring adequate selenium intake and maximizing selenium status in the presence of an elevated cancer risk is appropriate.



 


 

Increased Risk of Prostate Cancer

In one study, the risk of prostate cancer for men receiving a daily supplement of 200mcg per day of selenium was found to be one-third that of those receiving a placebo.



 


 

Increased Risk of Ovarian Cancer

20,305 American women were followed prospectively for 20 years. Initial serum selenium levels were inversely related to the risk of ovarian cancer. [J Natl Cancer Inst 88(1): pp.32-7, 1996]



 


 

Increased Risk of Colon Cancer

Blood levels of selenium have been reported to be low in patients with a variety of cancers including colon cancer. People with the lowest blood levels of selenium have an increased risk of dying from cancer compared with those who had the highest selenium levels.



 

Increased Risk of Melanoma

Serum selenium levels were inversely related to the degree of disease severity in 200 cases of melanoma studied. As selenium has established cancer prevention effects, its use to reduce the risk of melanoma is advisable.



Skin-Hair-Nails  

Adult Acne

See link to Vitamin E.



 

Adolescent Acne

Acne in both men and women can show improvement with vitamin E and selenium treatment.



Tumors, Malignant  

Leukemia

In evaluating 59 patients with lymphoid malignancies such as Hodgkin’s disease, non-Hodgkin’s lymphoma, multiple myeloma and chronic lymphocytic leukemia, serum selenium concentrations were significantly lower in patients than in controls. Clinical stage was inversely associated with selenium levels.



 


 

Melanoma

Serum selenium levels were inversely related to the degree of disease severity in 200 cases of melanoma studied. As selenium has established cancer prevention effects, its use to reduce the risk of melanoma is advisable.



 

Colon Cancer

Selenium supplementation was reported to improve immune function in colon cancer patients, but no long-term follow-up was done to evaluate whether these patients ultimately lived longer or fared better.



Uro-Genital  


 

Possible Pregnancy-Related Issues

A small study of infertile women and women with a history of miscarriage suggests that low levels of magnesium may impair reproductive function, and may contribute to miscarriage. Oxidation, a process that is damaging to cell membranes, can lead to loss of magnesium. The same study suggests that the antioxidant selenium protects the cell membrane, thereby maintaining appropriate levels of magnesium. The authors of the study suggest taking both magnesium and selenium supplements.

Women who have miscarried have lower levels of selenium than women who carry a pregnancy to full term. Although the authors of the above-mentioned study do not specify the exact amount to take, the recommended doses are generally 300 to 400mg per day of magnesium and 200mcg per day of selenium.



 

Female Infertility

A deficiency of selenium can lead to infertility in women.



Key

May do some good
Likely to help
Highly recommended

Glossary

Selenium

An essential element involved primarily in enzymes that are antioxidants. Three selenium- containing enzymes are antioxidant peroxidases and a fourth selenium-containing enzyme is involved in thyroid hormone production. The prostate contains a selenium-containing protein and semen contains relatively large amounts of selenium. Clinical studies show that selenium is important in lowering the risk of several types of cancers. In combination with Vitamin E, selenium aids the production of antibodies and helps maintain a healthy heart. It also aids in the function of the pancreas, provides elasticity to tissues and helps cells defend themselves against damage from oxidation.

Mineral

Plays a vital role in regulating many body functions. They act as catalysts in nerve response, muscle contraction and the metabolism of nutrients in foods. They regulate electrolyte balance and hormonal production, and they strengthen skeletal structures.

Vitamin E

An essential fat-soluble vitamin. As an antioxidant, helps protect cell membranes, lipoproteins, fats and vitamin A from destructive oxidation. It helps protect red blood cells and is important for the proper function of nerves and muscles. For Vitamin E only, 1mg translates to 1 IU.

Microgram

(mcg): 1/1,000 of a milligram in weight.

Gastrointestinal

Pertaining to the stomach, small and large intestines, colon, rectum, liver, pancreas, and gallbladder.

Amino Acid

An organic acid containing nitrogen chemical building blocks that aid in the production of protein in the body. Eight of the twenty-two known amino acids are considered "essential," and must be obtained from dietary sources because the body can not synthesize them.

Yeast

A single-cell organism that may cause infection in the mouth, vagina, gastrointestinal tract, and any or all bodily parts. Common yeast infections include candidiasis and thrush.

Sodium

An essential mineral that our bodies regulate and conserve. Excess sodium retention increases the fluid volume (edema) and low sodium leads to less fluid and relative dehydration. The adult body averages a total content of over 100 grams of sodium, of which a surprising one-third is in bone. A small amount of sodium does get into cell interiors, but this represents only about ten percent of the body content. The remaining 57 percent or so of the body sodium content is in the fluid immediately surrounding the cells, where it is the major cation (positive ion). The role of sodium in the extracellular fluid is maintaining osmotic equilibrium (the proper difference in ions dissolved in the fluids inside and outside the cell) and extracellular fluid volume. Sodium is also involved in nerve impulse transmission, muscle tone and nutrient transport. All of these functions are interrelated with potassium.

Naturopathy

Medical practice using herbs and other various methods to produce a healthy body state by stimulating innate defenses without the use of drugs.

Protein

Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.

Placebo

A pharmacologically inactive substance. Often used to compare clinical responses against the effects of pharmacologically active substances in experiments.

Cancer

Refers to the various types of malignant neoplasms that contain cells growing out of control and invading adjacent tissues, which may metastasize to distant tissues.

Prostate

The prostate gland in men that surrounds the neck of the bladder and the urethra and produces a secretion that liquefies coagulated semen.

Esophagus

Commonly called the "food pipe", it is a narrow muscular tube, about nine and a half inches long, that begins below the tongue and ends at the stomach. It consists of an outer layer of fibrous tissue, a middle layer containing smoother muscle, and an inner membrane, which contains numerous tiny glands. It has muscular sphincters at both its upper and lower ends. The upper sphincter relaxes to allow passage of swallowed food that is then propelled down the esophagus into the stomach by the wave-like peristaltic contractions of the esophageal muscles. There is no protective mucosal layer, so problems can arise when digestive acids reflux into the esophagus from the stomach.

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