Selenium can be a great healer

For over 30 years I have been researching the health effects of the mineral selenium. I have looked at hundreds of scientific studies from all over the world and I have treated thousands of patients, with selenium supplements. Selenium is obtained through diet and acts in the body as a “cleaning up” agent, or antioxidant, which neutralises toxic substances Without these antioxidants, cell damage occurs, and serious disease, and even death, may occur.

Selenium acts as a co-factor for several strategic antioxidant enzymes in the body called selenoproteins. These selenoproteins recycle cellular antioxidants, especially the body’s most powerful antioxidant called glutathione. This preservation of glutathione reduces oxidative stress, which is the main cause of degenerative diseases and premature aging

Put in laymen’s terms selenium is a tireless repairer and protector of your cells.

Selenium's Health Benefits

Not only does selenium reduce our risk of many types of cancer, it has a lot of other health benefits, which have been shown in a large number of clinical studies.

Selenium exerts health benefits in the following areas -

  • Autoimmune problems
  • Cardiovascular disease including atherosclerosis and strokes
  • Arthritis including osteoarthritis, rheumatoid arthritis and psoriatic arthritis
  • Neurological diseases including Alzheimer's disease
  • Pancreatitis (inflammation of the pancreas)
  • Thyroid Problems – both under and overactive thyroid states
  • Selenium concentration is higher in the thyroid gland than in any other organ in the body; in other words the thyroid gland accumulates selenium. Like iodine, selenium has important functions in thyroid hormone manufacture. Selenium is required by the cells to covert thyroid hormone into its active form. If you are low in selenium your thyroid function will be sluggish and you will be fatigued and inclined to gain weight.
  • Viral infections including HIV (which causes AIDS), and hepatitis. British researcher Margaret Rayman has shown that viruses can become much more dangerous in people who are selenium deficient. This includes hepatitis viruses and influenza and viral encephalitis.


Selenium: What Forms Protect Against Cancer?

Recent research data has stimulated medical interest in the specific anti-cancer properties of the mineral selenium. Researchers have found that selenium can influence gene expression to suppress a protein that regulates tumor onset, growth, and spread (metastasis).

It is important to know that there are several forms of selenium and each has special anti-cancer effects.

New research reveals that these forms of selenium have the ability to fight cancers of the colonand prostate gland.

In one study, older people taking 200 mcg of selenium daily had their risk of dying from all cancers reduced by a whopping 50%.


Selenium deficiency increases the risk of cancer

Large-scale epidemiologic studies have repeatedly shown that populations with low selenium levels are at significantly increased risk for developing many different types of cancer. These studies confirm that adequate dietary selenium exerts preventive effects on common cancers.

Multiple studies show that low selenium levels in the blood, hair, or nail clippings are associated with a two to threefold increase in overall cancer risk. For some types of cancer such as thyroid cancer, the risk rises to nearly 8-fold. Selenium deficiencies are now known to increase risk of cancers of the lung, bladder, stomach, esophagus, and liver.

A meta-analysis of nine controlled clinical trials with 152,538 participants proved that selenium supplementation reduced the risk for ALL cancers by 24%. This cancer-preventive effect was higher (36%) in people with low body selenium levels.

Three forms of Selenium are required for Cancer Prevention

Humans obtain selenium from a variety of foods (plant and animal sources) and this occurs in these foods in several different forms; each form has its own unique effects.

The three forms of selenium most active in preventing cancer are –

  • Sodium selenite
  • L-selenomethionine
  • Selenium-methyl L-selenocysteine.


Let’s look at their important differences –

L-selenomethionine increases cancer cell death by apoptosis (cancer cell suicide), but only in cells with an intact "suicide" gene called p53.34.

Selenium-methyl L-selenocysteine induces apoptosis in mutated cancer cells that lack this suicide gene.

Inorganic sodium selenite more effectively increases genetic expression of the selenium-containing antioxidant enzyme glutathione peroxidase.

All three selenium compounds stimulate cell death in various types of cancer, but each compound is better at destroying some cancers than others.

In general, the three selenium compounds complement one another in the ways they affect gene expression of proteins that control cancer prevention and suppression.

Because of these synergies between the different forms of selenium you can understand why all 3 forms of selenium taken together – namely L-selenomethionine, selenium-methyl L-selenocysteine, and sodium selenite are much more effective at killing off early or developing cancers in your body.

  • Note: Most people, including many medical doctors, do not know that selenium is available in several different forms which can complement each other.


 Selenium-Methyl L-Selenocysteine

Selenium-methyl L-selenocysteine is an organic combination of selenium with a sulfur-containing amino acid called L-cysteine. It is the most potent form of selenium known in nature, and Selenium-methyl L-selenocysteine is found in plants in the allium family (such as garlic and onions) which are grown in selenium-enriched soils.

Selenium-methyl L-selenocysteine restores proteins needed for normal circadian (24-hour) rhythms in the body. Disruptions in circadian rhythms (such as in shift workers or insomniacs) can be associated with an increased risk of several forms of cancer, most notably breast cancers. By promoting better regulation of circadian rhythm, selenium-methyl L-selenocysteine, balances the levels of melatonin and estrogen receptors related to the aggressiveness of breast cancers.

Selenium-methyl L-selenocysteine has the effect of inhibiting new blood vessel formation(angiogenesis) in tumors; this effect reduces tumor growth. Selenium-methyl L-selenocysteine has shown positive synergistic effects with various chemotherapy drugs, including those used in prostate and breast cancers.

If selenium-methyl L-selenocysteine is given along with the-breast cancer drug tamoxifen, it can enhance that drug's ability to inhibit growth of breast cancers implanted into mice. Such studies have been positive enough that selenium-methyl L-selenocysteine is now being specifically developed for breast cancer chemoprevention.

Sodium Selenite

Sodium selenite destroys cancer cells in different types of cancers through a variety of mechanisms. It generates toxic free radicals (reactive oxygen species) which target the destruction of mitochondria that exist in cancer cells, but not in healthy cells.

Sodium selenite promotes the repair of damaged genes (DNA segments); this reduces the risk of new cancers forming.

It is quite complex and intriguing to know that sodium selenite can decrease a protein called Bcl-2 that is abnormally elevated in cancer cells. Bcl-2 prevents the natural death of cancer cells by apoptosis. This explains why sodium selenite increases cancer cell death by suicide (apoptosis).

Numerous human studies with sodium selenite support the use of this form of selenium as a possible adjunct therapy for cancer patients and for preventing new or recurring cases of cancer.

In a randomized controlled clinical trial of sodium selenite using 200 mcg per day versus placebo in patients with aggressive head and neck cancers, the supplemented patients showed an increased ability to destroy cancer cells. Another study demonstrated that temporary use of 1,000 mcg of sodium selenite in patients with oral tumors effectively reduced potentially deadly swelling in these patients after surgery. Sodium selenite in patients with newly diagnosed non-Hodgkin's lymphoma increased the response rate to chemotherapy by 50% compared to a placebo group, and significantly increased overall survival time.

Selenium has also been studied in the context of breast cancer. In a group of women with the high breast cancer-risk BRCA1 gene mutation, a reduction in new breast cancer cases was demonstrated during a double-blind supplementation trial.



L-selenomethionine is an organic form of selenium combined with the sulfur bearing amino acid called L-methionine. It is the form of selenium found in most preparations of selenium-enriched yeast, which has been used in many clinical trials.

Laboratory tests demonstrate that L-selenomethionine inhibits growth of cancer cells at rates more than a thousand times greater than it does healthy normal tissue.

In patients with pre-cancerous tissue in their esophagus, 200 mcg of L-selenomethionine daily slowed the progression of potential cancerous cells and triggered regression of pre-cancerous cells to normal. This anti-cancer effect was stronger in patients with earlier changes than in those with more advanced cell abnormalities; this highlights the importance of early supplementation.

Dr. Larry C. Clark of the University of Arizona did a trial to prevent skin cancers in 1996 with a daily 200 mcgsupplement of L-selenomethionine. This was found to be ineffective at preventing skin cancer. However the supplemented patients were found to reap other anti-cancer benefits – they were significantly protected from death by all cancers (a 50% reduction compared with controls) and from developing any cancer (a 37% reduction). These exciting and unanticipated results were so powerful that the blinded phase of the study was stopped early to allow all subjects to achieve maximum protection from selenium

Subsequent studies by Dr. Clark demonstrated a 63% reduction in occurrence of prostate cancer among men with a history of previous cancers.

Selenium's Anti-Cancer Mechanisms

Scientific studies now show multiple different mechanisms by which selenium prevents potentially cancerous cells from growing into a fully developed tumor:

  1. Regulation of lipoxygenase enzymes which produce inflammatory molecules that stimulate cancer growth
  2. Reduction of oxidative stress that causes free radical damage
  3. Protection of seleno- proteins, which recycle antioxidants
  4. Detoxification of the body from cancer-causing heavy metals
  5. Induction of protective "phase-2" liver enzymes that neutralize many carcinogenic toxins
  6. Inhibition of DNA alterations (genetic damage), which initiates cancerous changes in cells
  7. Inactivation of molecular transcription factors required by cancer cells to support their growth and development
  8. Shutting down of the essential cell replication cycle needed by cancer cells to produce their explosive growth
  9. Induction of apoptosis, the programmed cell death, that is missing in cancerous cells allowing them to continue to reproduce indefinitely or live forever
  10. Enhanced immune system activity to detect and destroy incipient cancer cells
  11. Down-regulation of sex hormone receptors used by certain cancers to sustain their growth

These mechanisms act together to maximize cancer protection.

There is a large amount of scientific evidence to show that selenium has anti-cancer effects, and that selenium supplements are worthwhile.

There are skeptics who promote the theory that selenium is useless or even dangerous and many people remain confused by this attitude. I think this skeptical attitude and misinformation mainly stems from the publication in 2009 of a single negative study, about the efficiency of selenium in cancer prevention.

This negative study is known as SELECT (Selenium and Vitamin E Cancer Prevention Trial). This study appeared to show that selenium, alone or in combination with vitamin E, had no detectable effect on preventing cancers. Many experts have subsequently questioned the SELECT trial's methodology and conclusions. One problem with that study was that it used only a single form of selenium which is just one of several different forms of selenium available. Another significant fault in this study is that it used synthetic vitamin E (alpha tocopherol), which displaced critical gamma tocopherol from cells, thereby increasing cancer risk



Selenium is a trace element now recognized to be essential in human nutrition. It has attracted increasing scientific interest over the past few years for its powerful cancer-preventing potential. Selenium occurs in multiple forms in nature, three of which are especially important in preventing human cancers. Each of these three forms of selenium has produced intriguing findings. Laboratory studies reveal the reason: each form of selenium has a unique suite of mechanisms, and each affects different cancer types somewhat differently. The human body handles each form of selenium in a different fashion, and each form contributes uniquely to preventing cancer from emerging. Only by combining all three forms of selenium can you be sure of optimizing your cancer risk reduction. In that way you'll be taking advantage of all of the 12 known mechanisms by which selenium compounds prevent cancer.


Selenium Deficiency

Selenium deficiency in humans and animals is common worldwide because of –

Processed foods and mass production of foods

Poor absorption of minerals is common in people with intestinal disorders such as celiac disease, Crohn’s disease, cystic fibrosis etc. or those taking antacid drugs.

Selenium levels are often low in people living with chronic viral infections such as HIV and hepatitis

Selenium deficiency is widespread throughout Australia, occurring in large parts of Western Australia, and in parts of South Australia, Victoria, Queensland, New South Wales and Tasmania. Deficient prone areas are coastal sandy soils, acidic soils, sedimentary and granite soils, usually in high rainfall regions (made worse by high superphosphate application and clover dominance).

China has soils which are extremely deficient in selenium. Studies in the Jiangsu Province of China have indicated a reduction in the prevalence of many diseases by taking selenium supplements. In Finland, selenium salts are added to chemical fertilizers, as a way to increase selenium in soils.

Average selenium intakes are also low in some European countries, especially among populations consuming vegan diets. Although intakes in New Zealand were low in the past, they rose after the country increased its importation of high-selenium wheat.

Selenium concentrations soils in USA vary a lot and to see a map visit-

Measurement of Selenium in the Body

  1. The most commonly used measures of selenium status are plasma and urine selenium concentrations. Concentrations in blood and urine represent recent selenium intake. Because selenium is concentrated inside the body’s cells and also in specific organs such as the thyroid and breast tissue, a blood test for selenium levels is not an accurate measurement of total body selenium status. The blood and urine selenium levels are just the tip of the iceberg – in other words they do not represent the true total body selenium status. These levels can be in the normal range but you may be deficient.
  2. Plasma or serum selenium concentrations of 8 mcg/dL or higher in healthy people typically meet needs for selenoprotein synthesis
  3. Analyses of hair or nail selenium content can be used to monitor longer-term intakes over months or years. These tests can become unreliable if there are hair and nail diseases.
  4. Measurement of one of the selenoproteins (such as glutathione peroxidase and selenoprotein P); this can be used as a functional measure of selenium status.


Can selenium be toxic?

Long term excessive intakes of selenium supplements may cause –

A garlic odor in the breath

A metallic taste in the mouth

Hair and nail loss or brittleness

Lesions in the skin and nervous system

Nausea and diarrhea

Mottled teeth


Brazil nuts contain very high amounts of selenium (68–91 mcg per nut) and may cause selenium toxicity if consumed regularly in large amounts. Soils vary so much that not all Brazil nuts are this high in selenium. Acute selenium toxicity has resulted from taking mis-formulated over-the-counter products containing very large amounts of selenium. Over 200 people experienced severe adverse reactions from taking a liquid supplement containing 200 times the labeled amount of selenium. Acute selenium toxicity is usually caused by overdosing with large numbers of tablets or by an industrial accident and can cause severe gastrointestinal and neurological symptoms, acute respiratory distress syndrome, heart attack, muscle pain, tremors, dizziness, kidney failure, heart failure, and, in extremely rare cases, death.

The Food and Nutrition Board (FNB) has established Upper Limits for selenium from both food and supplements - see Table 1


Table 1: Tolerable Upper Intake Levels (ULs) for Selenium
Age Male Female Pregnancy Lactation
Birth to 6 months 45 mcg 45 mcg
7–12 months 60 mcg 60 mcg
1–3 years 90 mcg 90 mcg
4–8 years 150 mcg 150 mcg
9–13 years 280 mcg 280 mcg
14–18 years 400 mcg 400 mcg 400 mcg 400 mcg
19+ years 400 mcg 400 mcg 400 mcg 400 mcg



Some interesting case histories

Plantar warts

One of my patients had a recurrent plantar wart in the sole of his foot. It kept regrowing after surgery and was increasingly painful. I knew immediately that he was selenium deficient as a plantar wart is caused by a wart virus. If someone has plenty of selenium stores in their body the wart virus cannot flourish and warts do not grow or disappear. I prescribed 200mcg of selenomethionine daily and within 6 weeks the plantar wart was gone – impressive eh !

Laryngeal warts

Several years ago I received an email from a concerned grandmother who asked me for help. Her 5 year old granddaughter had undergone 4 surgeries to her larynx (vocal cords) to remove recurrent laryngeal warts. These warts were becoming larger and the doctors were looking at using strong anti-viral chemotherapy to inject into the warts on her vocal cords.

I told this desperate grandmother that her granddaughter was extremely deficient in selenium and perhaps zinc and iodine. She may have also been gluten intolerant, as this aggravates selenium deficiency and weakens cellular immunity. Her granddaughter needed substantial doses of selenium, and possibly zinc and iodine and also needed to have her vitamin D levels checked. Unfortunately I never heard from her again.


Case History in a dog with skin problems

Let me tell you a little story that happened in 2011 concerning my bull mastiff puppy Harley who was 4 months old. Well much to my horror, this perfect specimen of a puppy caught the mange from another dog. The local vet did not realize Harley had mange, as it became infected with bacteria. Harley was then treated with antibiotics and got an allergy, which made his rash worse. I scoured the Internet with Google scholar and made the diagnosis my self – Harley had the dreaded mange!

I was away from home for 7 days and so I called a wonderful vet Dr Ian Billinghurst who is a holistic vet who has written a book titled Give Your Dog a Bone. Dr Billinghurst told me to purchase the liquid treatment for mange called Advocate. So I did this but I could not apply it to Harley until I returned home. In the meantime I called my uncle Robert who lives with Harley and I told Robert to give Harley 2 selenium tablets with his meal, each selenium tablet containing 100mcg of selenium. Well Robert misunderstood my directions and gave Harley 2 selenium tablets, three times daily with his meals, which provided a total daily dose of 600mcg of selenium. Now Harley is 4 months old and weighs 60 pounds, so that’s an excessive dose of selenium.

When I finally arrived back home and Harley bounded into my arms we had a cuddle! I examined his skin and was delighted – his mange was 90% gone! When I discovered Robert’s mistake and realized that Harley had been taking 600mcg of selenium daily for 7 days I understood the connection. The stubborn rash and sores caused by the mange had been almost eliminated by the selenium, as Robert had not been giving Harley anything else that was different. What had happened is that the selenium had strengthened Harley’s cellular immune system quickly and it had eradicated most of the infection. Harley was a very happy little man but just to be sure we applied the Advocate liquid.


Human Papilloma Virus

I have another patient who suffered terribly because her cellular immune system was not working efficiently. This had enabled the human papilloma virus (HPV) to spread rapidly in the mucous membranes and skin (epidermal layers) of her vulva, anus, rectum and cervix. She was a young woman who desired to have a family and was anxious this chronic infection would reduce her chances. Conventional medicine and surgery had failed as the virus kept recurring. She did not have any other health problems such as anaemia, cancer or AIDS which could be causing immune incompetence.

Why was her cellular immune system so incompetent?

Well, probably for several reasons-

A deficiency of selenium for sure

Possible deficiencies of zinc, iodine and vitamin D

An inflamed gut which was not able to absorb the nutrients required for immune-competence – the most likely culprit here being gluten intolerance. Be aware that this is not always the same thing as coeliac disease.

Without correcting the gut and liver issues of this patient we would not achieve complete success. She would require a large dose of selenium, say 400mcg daily, until this virus was controlled.

Severe and/or chronic infections with the HPV virus can lead to cancer of the cervix, vagina, vulva, anus, rectum, mouth and throat. Well known actress Farrah Fawcett died with this preventable cancer at a relatively young age.


Some selected studies of selenium

In studies with low-dose selenite (up to 300 micrograms a day), cancer patients reported a better quality of life. Side effects were not reported. Analysis of the immune system revealed a stimulation of B19 lymphocytes and natural killer cells.

In Germany, a country with selenium deficiency, clinical studies are now carried out on the effects of selenium as a drug to reduce side effects of chemotherapy and radiotherapy, enhance quality of life by reducing toxic side effects and help to restore immune function.

Study results indicate that low selenium status is strongly associated with colorectal (bowel) cancer (including extension and severity of the disease). This finding means that selenium supplementation could be important in prevention or even adjuvant therapy of colorectal cancer.

There are a large number of studies showing selenium to be an effective adjunctive therapy against HIV infection.

Observational studies have found an association between lower selenium concentrations in people with AIDS (HIV infection) and an increased risk of cardiomyopathy (heart muscle disease) and death. Some randomized clinical trials of selenium supplementation in adults with HIV have found that selenium supplementation can reduce the risk of hospitalization and prevent increases of HIV-1 viral load; preventing HIV-1 viral load progression can lead to increases in numbers of CD4 cells, a type of white blood cell that fights infection.

One finding that shows up repeatedly is that adults living in selenium deficient geographic areas have severely reduced life spans. Heart muscle damage is common at autopsy in these selenium-deficient cases. In 25 cities in the United States, low selenium correlates with high rates of heart attack and cancer. Selenium prevents toxic effects of cadmium and mercury, and helps to modulate the active transport of calcium out of the arterial system.

A Chinese study in 130,471 people over eight years showed that selenium reduced the risk of liver cancer in people with viral hepatitis. The group who received supplemental selenium had a 35.1% reduction in the incidence of primary liver cancer compared to the placebo group which did not receive selenium. When selenium supplementation was discontinued, incidences of primary liver cancer began to increase, indicating that continuous intake of supplemental selenium is essential to sustain its protective effect against liver cancer. In a sub-group of this study that evaluated 113 patients infected with the hepatitis B virus, the daily intake of 200 mcg of selenium resulted in zero rates of liver cancer, compared to 7 liver cancers in the placebo group (not receiving selenium supplements). When the selenium group stopped taking the selenium supplement, primary liver cancer rates began to increase.

Another study examined the association between plasma selenium levels and the risk of liver cancer (hepatocellular carcinoma) among chronic carriers of hepatitis B and/or C virus in a cohort of 7,342 men. This 5.3 year study showed that those with low blood selenium levels were 47% more likely to develop primary liver cancer compared to those with higher levels of selenium.

A small case history report showed significant benefit to treating advanced hepatitis C patients with a combination of alpha lipoic acid, silymarin (milk thistle) and selenium. Here is what the physician reported regarding his clinical observations:

"The triple antioxidant combination of alpha-lipoic acid, silymarin and selenium was chosen for a conservative treatment of hepatitis C because these substances protect the liver from free radical damage, increase the levels of other fundamental antioxidants, and interfere with viral proliferation. The 3 patients presented in this paper followed the triple antioxidant program and recovered quickly and their laboratory values remarkably improved. Furthermore, liver transplantation was avoided and the patients are back at work, carrying out their normal activities, and feeling healthy."

The physician noted that supplementation with these three nutrients is relatively inexpensive compared to more than $300,000 for liver transplant surgery. He also noted that other problems with liver transplant surgery include a shortage of available livers, re-infection of the new liver with residual virus, and high mortality rates associated with the procedure including greater risks of cancer from the immune-suppressing drugs given to suppress organ rejection.

Another study involving 20,847 people showed that those supplementing with selenium showed a 70% reduction in becoming infected with the hepatitis B virus compared to surrounding populations not receiving supplemental selenium.


Scientific references for selenium

Brozmanova J. Selenium and cancer: from prevention to treatment. Klin Onkol. 2011; 24(3):171-9.

Naithani R. Organoselenium compounds in cancer chemoprevention. Mini Rev Med Chem. 2008 Jun;8 (7):657-68.

Clark LC, et al. Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer Study Group. JAMA. 1996 Dec 25; 276(24):1957-63.

Ganther HE. Selenium metabolism, selenoproteins and mechanisms of cancer prevention: complexities with thioredoxin reductase. Carcinogenesis. 1999 Sep;20(9):1657-66.

Rayman MP. Selenium in cancer prevention: a review of the evidence and mechanism of action. Proc Nutr Soc. 2005 Nov;64(4):527-42.

Fleet JC. Dietary selenium repletion may reduce cancer incidence in people at high risk who live in areas with low soil selenium. Nutr Rev. 1997 Jul;55(7):277-9.

Peters U, Takata Y. Selenium and the prevention of prostate and colorectal cancer. Mol Nutr Food Res. 2008 Nov;52(11):1261-72.

Yoshizawa K, et al. Study of pre-diagnostic selenium level in toenails and the risk of advanced prostate cancer. J Natl Cancer Inst. 1998 Aug 19;90 (16):1219-24.

Ghadirian P, et al. A case-control study of toenail selenium and cancer of the breast, colon, and prostate. Cancer Detect Prev. 2000;24(4):305-13.

Willett WC, et al. Pre-diagnostic serum selenium and risk of cancer. Lancet. 1983 Jul 16; 2 (8342):130-4.

Salonen JT, et al. Association between serum selenium and the risk of cancer. Am J Epidemiol. 1984 Sep;120 (3):342-9.

Glattre E, et al. Prediagnostic serum selenium in a case-control study of thyroid cancer. Int J Epidemiol. 1989 Mar;18 (1):45-9.

Mark SD, Qiao YL, et al. Prospective study of serum selenium levels and incident esophageal and gastric cancers. J Natl Cancer Inst. 2000 Nov 1;92(21):1753-63.

Van den Brandt PA, et al. A prospective cohort study on selenium status and the risk of lung cancer. Cancer Res. 1993 Oct 15;53 (20):4860-5.

Helzlsouer KJ, Comstock GW, Morris JS. Selenium, lycopene, alpha-tocopherol, beta-carotene, retinol, and subsequent bladder cancer. Cancer Res. 1989 Nov 1;49(21):6144-8.

El-Bayoumy K. The negative results of the SELECT study do not necessarily discredit the selenium-cancer prevention hypothesis. Nutr Cancer. 2009;61(3):285-6.

Marshall JR, et al. Methyl Selenocysteine: single-dose pharmacokinetics in men. Cancer Prev Res (Phila). 2011 Aug 16.

Fleming J, Ghose A, Harrison PR. Molecular mechanisms of cancer prevention by selenium compounds. Nutr Cancer. 2001;40 (1):42-9.

Sinha R, El-Bayoumy K. Apoptosis is a critical cellular event in cancer chemoprevention and chemotherapy by selenium compounds. Curr Cancer Drug Targets. 2004 Feb;4 (1):13-28.

Fang MZ, Zhang X, Zarbl H. Methylselenocysteine resets the rhythmic expression of circadian and growth-regulatory genes disrupted by nitrosomethylurea in vivo. Cancer Prev Res (Phila). 2010 May;3(5):640-52.

Bhattacharya A. Methylselenocysteine: a promising antiangiogenic agent for overcoming drug delivery barriers in solid malignancies for therapeutic synergy with anticancer drugs. Expert Opin Drug Deliv. 2011 Jun;8(6):749-63.

Bhattacharya A, et al. Magnetic resonance and fluorescence-protein imaging of the anti-angiogenic and anti-tumor efficacy of selenium in an orthotopic model of human colon cancer. Anticancer Res. 2011 Feb;31(2):387-93.

Brozmanova J, Manikova D. Selenium: a double-edged sword for defense and offence in cancer. Arch Toxicol. 2010 Dec;84 (12):919-38.

Mahn AV, Toledo HM. Organic and inorganic selenium compounds produce different protein patterns in the blood plasma of rats. Biol Res. 2009;42(2):163-73.

Barger JL, et al. Gene expression profiling reveals differential effects of sodium selenite, selenomethionine, and yeast-derived selenium in the mouse. Genes Nutr. 2011 Aug 17.

Burk RF. Effects of chemical form of selenium on plasma biomarkers in a high-dose human supplementation trial. Cancer Epidemiol Biomarkers Prev. 2006 Apr;15 (4):804-10.

El-Sayed WM. Effect of selenium-containing compounds on hepatic chemoprotective enzymes in mice. Toxicology. 2006 Mar 15;220 (2-3):179-88.

Suzuki M. Differential apoptotic response of human cancer cells to organoselenium compounds. Cancer Chemother Pharmacol. 2010 Aug; 66(3):475-84.

Lunoe K. Investigation of the selenium metabolism in cancer cell lines. Metallomics. 2011 Feb; 3 (2):162-8.

Broome CS, et al. An increase in selenium intake improves immune function and poliovirus handling in adults with marginal selenium status. Am J Clin Nutr. 2004 Jul;80(1):154-62.

Weekley CM, et al. Metabolism of selenite in human lung cancer cells: X-ray absorption and fluorescence studies. J Am Chem Soc. 2011 Sep 28.

Chen XJ, Duan FD. Sodium selenite-induced apoptosis mediated by ROS attack in human osteosarcoma U2OS cells. Biol Trace Elem Res. 2011 Aug 9.

Fu L, Liu Q. Proteomic study on sodium selenite-induced apoptosis of human cervical cancer HeLa cells. J Trace Elem Med Biol. 2011 Jul;25 (3):130-7.

Ma Q, Fang H, et al. Superoxide flashes: early mitochondrial signals for oxidative stress-induced apoptosis. J Biol Chem. 2011 Aug 5;286(31):27573-81.

Li W, Zhu Y, Yan X, et al. The prevention of primary liver cancer by selenium in high risk populations. Zhonghua Yu Fang Yi Xue Za Zhi. 2000 Nov;34 (6):336-8.

Dziaman T, et al. Selenium supplementation reduced oxidative DNA damage in adnexectomized BRCA1 mutations carriers. Cancer Epidemiol Biomarkers Prev. 2009 Nov;18(11):2923-8.

Kiremidjian-Schumacher L, et al. Selenium and immunocompetence in patients with head and neck cancer. Biol Trace Elem Res. 2000 Feb;73(2):97-111.

Asfour IA. Effect of high-dose sodium selenite therapy on leukocyte apoptosis in non-Hodgkin's lymphoma patients. Biol Trace Elem Res. 2006 Apr; 110(1):19-32.

Asfour IA, et al. Impact of high-dose sodium selenite therapy on Bcl-2 expression in adult non-Hodgkin's lymphoma patients: correlation with response and survival. Biol Trace Elem Res. 2007 Winter; 120(1-3):1-10.

Nemec KN, Khaled AR. Therapeutic modulation of apoptosis: targeting the BCL-2 family at the interface of the mitochondrial membrane. Yonsei Med J. 2008 Oct 31;49 (5):689-97.

Asfour IA, et al. High-dose sodium selenite can induce apoptosis of lymphoma cells in adult patients with non-Hodgkin's lymphoma. Biol Trace Elem Res. 2009 Mar;127 (3):200-10.

Li ZS, Shi KJ. Downregulation of protein kinase Calpha was involved in selenite-induced apoptosis of NB4 cells. Oncol Res. 2010;19(2):77-83.

Zimmermann T. Reduction of postoperative lymphedema after oral tumor surgery with sodium selenite. Biol Trace Elem Res. 2005 Sep; 106(3):193-203.

Schrauzer GN. Selenomethionine: a review of its nutritional significance, metabolism and toxicity. J Nutr. 2000 Jul;130 (7):1653-6.

Combs GF. Reduction of cancer mortality and incidence by selenium supplementation. Med Klin (Munich). 1997 Sep 15;92 Suppl 3:42-5.

Combs GF, Jr., Clark LC, Turnbull BW. Reduction of cancer risk with an oral supplement of selenium. Biomed Environ Sci. 1997 Sep;10 (2-3):227-34.

Clark LC, et al. Decreased incidence of prostate cancer with selenium supplementation: results of a double-blind cancer prevention trial. Br J Urol. 1998 May;81(5):730-4.

Limburg PJ, et al. Randomized, placebo-controlled, esophageal cancer chemoprevention trial of selenomethionine and celecoxib. Gastroenterology. 2005 Sep;129 (3):863-73.

Redman C, et al. Inhibitory effect of selenomethionine on the growth of three selected human tumor cell lines. Cancer Lett. 1998 Mar 13;125(1-2):103-10.

Vidlar A, et al. The safety and efficacy of a silymarin and selenium combination in men after radical prostatectomy - a six month placebo-controlled double-blind clinical trial. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2010 Sep;154(3):239-44.

Scientific opinion of the panel on nutrient sources added to food on Se-Methyl-L-Selenocysteine as a source of selenium added for nutritional purposes to food supplements following a request from the European Commission. The EFSA Journal (2009) 1067, 1-23.

Zhang X, Zarbl H. Chemopreventive doses of methylselenocysteine alter circadian rhythm in rat mammary tissue. Cancer Prev Res (Phila). 2008 Jul;1(2):119-27.

Bhattacharya A, et al. Inhibition of colon cancer growth by methylselenocysteine-induced angiogenic chemomodulation is influenced by histologic characteristics of the tumor. Clin Colorectal Cancer. 2009 Jul;8(3):155-62.

Li Z, Carrier L, Belame A, et al. Combination of methylselenocysteine with tamoxifen inhibits MCF-7 breast cancer xenografts in nude mice through elevated apoptosis and reduced angiogenesis. Breast Cancer Res Treat. 2009 Nov;118(1):33-43.

Bhattacharya A. Tumor vascular maturation and improved drug delivery induced by methylselenocysteine leads to therapeutic synergy with anticancer drugs. Clin Cancer Res. 2008 Jun 15;14(12):3926-32.

Cao S. Selective modulation of the therapeutic efficacy of anticancer drugs by selenium containing compounds against human tumor xenografts. Clin Cancer Res. 2004 Apr 1;10(7):2561-9.

Lee JT. Se-methylselenocysteine sensitized TRAIL-mediated apoptosis via down-regulation of Bcl-2 expression. Int J Oncol. 2009 May;34(5):1455-60.

Pan MH, et al. Se-methylselenocysteine inhibits lipopolysaccharide-induced NF-kappaB activation and iNOS induction in RAW 264.7 murine macrophages. Mol Nutr Food Res. 2011 May;55(5):723-32.

Johnson WD. Subchronic oral toxicity studies of Se-methylselenocysteine, an organoselenium compound for breast cancer prevention. Food Chem Toxicol. 2008 Mar;46(3):1068-78.

Wang L, et al. Methyl-selenium compounds inhibit prostate carcinogenesis in the transgenic adenocarcinoma of mouse prostate model with survival benefit. Cancer Prev Res (Phila). 2009 May;2(5):484-95.

Selenium may slow the march of AIDS. Press Release - The Pennsylvania State University. December 9, 2008.

Kalantari P et al. Thioredoxin Reductase-1 Negatively Regulates HIV-1 Transactivating Protein Tat-dependent Transcription in Human Macrophages. J Biol Chem. 2008 Nov 28; 283(48):33183-90.

Levander OA et al, Selenium and viral virulence, British Med Bull 1999; 55(3): 528-533

Nelson HK, et al. Host nutritional selenium status as a driving force for influenza virus mutations. FASEB J 2001;15:1846-1848

Hurwitz BE, et al. Suppression of HIV type 1 viral load with selenium supplementation: a randomized controlled trial. Arch Intern Med. 2007 Jan 22; 167(2):148-54.

Beck MA. Selenium deficiency & viral infection. J Nutr 2003;133 (5 Suppl 1):1463S-7S

Rayman MP. The importance of selenium to human health. Lancet 2000; 356:233-41

Rayman MP, Dietary selenium; time to act, British Medical Journal, Vol. 314, 387, Feb 1997

Selenium as a chemo preventative agent in human primary hepatocellular carcinoma

Yu SY, Zhu YJ, Li WG. Cancer Institute, Chinese Academy of Medical Sciences, Beijing 100021 and Qidong Liver Cancer Institute, Jiangsu, PR China.

Jolanta Czuczejko, et al. Selenium, glutathione and glutathione peroxidases in blood of patients with chronic liver diseases. Acta Biochimica Polonica, Vol. 50 No.4/2003

Beck MA, et al, Host nutritional status and its effect on a viral pathogen. J Infect Diseases 2000; 182 (Suppl): S93-6

Domingo E, RNA virus evolution, population dynamics and nutritional status. Biol Trace Elem Res 1997;56 (1):23-30

Stehbens W E. Oxidative stress in viral hepatitis & AIDS. Exp Mol Path 2004; 77(2):121-32

Sunde RA. Selenium. In: Bowman B, Russell R, eds. Present Knowledge in Nutrition. 9th ed. Washington, DC: International Life Sciences Institute; 2006:480-97

Davis CD. Selenium supplementation and cancer prevention. Curr. Nutr. Rep.2012; 1:16-23.

Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes: Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academy Press, Washington, DC, 2000.

Chun OK, et al. Estimation of antioxidant intakes from diet and supplements in U.S. adults. J Nutr 2010; 140:317-24.

Rayman MP. Food-chain selenium & human health: emphasis on intake. Br J Nutr 2008; 100:254-68

Rayman MP. Selenium and human health. Lancet 2012; 379:1256-68.

U.S. Department of Agriculture, Agricultural Research Service. USDA National Nutrient Database for Standard Reference, Release 25. 2012

Thomson CD, Chisholm A, McLachlan SK, Campbell JM. Brazil nuts: an effective way to improve selenium status. Am J Clin Nutr. 2008 Feb; 87(2):379-84.

Bodó ET, et al. Preparation, homogeneity and stability studies of a candidate LRM for Se speciation. Anal Bioanal Chem. 2003 Sep; 377(1):32-8.

Burk RF, et al. Effects of chemical form of selenium on plasma biomarkers in a high-dose human supplementation trial. Cancer Epidemiol Biomarkers Prev 2006; 15:804-10.

U.S. Department of Agriculture, Agricultural Research Service. What We Eat in America, 2009-2010

Bailey RL, et al. Dietary supplement use in the United States, 2003-2006. J Nutr 2011; 141:261-6

Laclaustra M, et al. Serum selenium and serum lipids in US adults: National Health and Nutrition Examination Survey (NHANES) 2003-2004. Atherosclerosis 2010; 210:643-8.

Xun P, et al. Distribution of toenail selenium levels in young adult Caucasians and African Americans in the United States: the CARDIA Trace Element Study. Environ Res 2011; 111:514-9

Kafai MR, Ganji V. Sex, age, geographical location, smoking, and alcohol consumption influence serum selenium concentrations in the USA: third National Health and Nutrition Examination Survey, 1988-1994. J Trace Elem Med Biol 2003; 17:13-8.

Chen J. An original discovery: selenium deficiency and Keshan disease (an endemic heart disease). Asia Pac J Clin Nutr 2012; 21:320-6.

Jirong Y, et al. Sodium selenite for treatment of Kashin-Beck disease in children: a systematic review of randomised controlled trials. Osteoarthritis Cartilage 2012; 20:605-13.

World Health Organization, Food and Agriculture Organization of the United Nations. Vitamin and Mineral Requirements in Human Nutrition. 2004

Tonelli M, et al. Trace elements in hemodialysis patients: a systematic review and meta-analysis. BMC Med 2009; 7:25.

Stone CA, et al. Role of selenium in HIV infection. Nutr Rev 2010; 68:671-81.

Baum MK, et al. High risk of HIV-related mortality is associated with selenium deficiency. J Acquired Immune Deficiency Syndrome Hum Retrovirol 1997; 15:370-4.

Twagirumukiza M, et al. Prevalence of dilated cardiomyopathy in HIV-infected African patients not receiving HAART: a multicenter, observational, prospective, cohort study in Rwanda. Curr HIV Res 2007; 5:129-37.

Campa A, et al. Mortality risk in selenium-deficient HIV-positive children. J Acquir Immune Defic Syndr Hum Retrovirol 1999; 15:508-13.

Kupka R, et al. Selenium levels in relation to morbidity and mortality among children born to HIV-infected mothers. Eur J Clin Nutr 2005; 59:1250-8.

Kupka R, et al. Selenium status, pregnancy outcomes, and mother-to-child transmission of HIV-1. J Acquir Immune Defic Syndr 2005; 39:203-10.

Burbano X, et al. Impact of a selenium chemoprevention clinical trial on hospital admissions of HIV-infected participants. HIV Clin Trials 2002; 3:483-91.

Hurwitz BE, et al. Suppression of human immunodeficiency virus type 1 viral load with selenium supplementation: a randomized controlled trial. Arch Intern Med 2007; 167:148-54.

Kupka R, et al. Randomized, double-blind, placebo-controlled trial of selenium supplements among HIV-infected pregnant women in Tanzania: effects on maternal and child outcomes. Am J Clin Nutr 2008; 87:1802-8.

Kupka R, et al. Effect of selenium supplements on hemoglobin concentration and morbidity among HIV-1-infected Tanzanian women. Clin Infect Dis 2009; 48:1475-8.

Allen NE, et al. Plasma selenium concentration and prostate cancer risk: results from the European Prospective Investigation into Cancer and Nutrition (EPIC). Am J Clin Nutr 2008; 88:1567-75.

Combs GF, et al. Chemopreventive agents: Selenium. Pharmacol Ther 1998; 79:179-92.

Dennert G, et al. Selenium for preventing cancer. Cochrane Database Syst Rev 2011:CD005195.

Brinkman M, et al. Are men with low selenium levels at increased risk of prostate cancer? Eur J Cancer 2006; 42:2463-71.

Bjelakovic G, et al. Systematic review: primary and secondary prevention of gastrointestinal cancers with antioxidant supplements. Aliment Pharmacol Ther 2008; 28:689-703.

Duffield-Lillico AJ, et al. Selenium supplementation, baseline plasma selenium status and incidence of prostate cancer: an analysis of the complete treatment period of the Nutritional Prevention of Cancer Trial. BJU Int 2003; 91:608-12.

Lippman SM, et al. The effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA 2009; 301:39-51

Klein EA, et al. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA 2011; 306:1549-1556.

Flores-Mateo G, et al. Selenium and coronary heart disease: a meta-analysis. Am J Clin Nutr 2006; 84:762-73.

Xun P, et al. Longitudinal association between toenail selenium levels & measures of subclinical atherosclerosis: the CARDIA trace element study. Atherosclerosis 2010; 210:662-7

Bleys J, et al. Serum selenium levels and all-cause, cancer, and cardiovascular mortality among US adults. Arch Intern Med 2008; 168:404-10.

Bleys J, et al. Serum selenium and peripheral arterial disease: results from the national health and nutrition examination survey, 2003-2004. Am J Epidemiol 2009; 169:996-1003.

Rayman MP, et al. Effect of supplementation with high-selenium yeast on plasma lipids: a randomized trial. Ann Intern Med 2011; 154:656-65.

Hercberg S, et al. The SU.VI.MAX Study: a randomized, placebo-controlled trial of the health effects of antioxidant vitamins and minerals. Arch Intern Med 2004; 164:2335-42.

Hercberg S, et al. Incidence of cancers, ischemic cardiovascular diseases and mortality during 5-year follow-up after stopping antioxidant vitamins and minerals supplements: a post-intervention follow-up in the SU.VI.MAX Study. Int J Cancer 2010; 127:1875-81.

Stranges S, et al. Effects of selenium supplementation on cardiovascular disease incidence and mortality: secondary analyses in a randomized clinical trial. Am J Epidemiol 2006; 163:694-9

Akbaraly TN, et al. Plasma selenium over time and cognitive decline in the elderly. Epidemiology 2007; 18:52-8.

Shahar A, et al. Plasma selenium is positively related to performance in neurological tasks assessing coordination and motor speed. Mov Disord 2010; 25:1909-15.

Berr C, et al. Cognitive decline is associated with systemic oxidative stress: the EVA study. Etude du Vieillissement Artériel. J Am Geriatr Soc 2000; 48:1285-91.

Gao S, et al. Selenium level & cognitive function in elderly Chinese. Am J Epidem 2007; 165:955-65

Perkins AJ, et al. Association of antioxidants with memory in a multiethnic elderly sample using the Third National Health and Nutrition Examination Survey. Am J Epidemiol 1999; 150:37-44

Kesse-Guyot E, et al. French adults' cognitive performance after daily supplementation with antioxidant vitamins and minerals at nutritional doses: a post hoc analysis of the Supplementation in Vitamins and Mineral Antioxidants (SU.VI.MAX) trial. Am J Clin Nutr 2011; 94:892-9.

Derumeaux H, et al. Association of selenium with thyroid volume and echo-structure in 35 to 60 year-old French adults. Eur J Endocrinol 2003; 148(3):309-15.

Rasmussen LB, et al. Selenium status, thyroid volume, and multiple nodule formation in an area with mild iodine deficiency. Eur J Endocrinol 2011;164:585-90.

Rayman MP, et al. Randomized controlled trial of the effect of selenium supplementation on thyroid function in the elderly in the United Kingdom. Am J Clin Nutr 2008; 87:370-8.

Marcocci C, et al. Selenium and the course of mild Graves' orbitopathy. N Engl J Med 2011; 364:1920-31.

Negro R, et al. The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies. J Clin Endocrinol Metab 2007; 92:1263-8.

Reid SM, et al. Interventions for clinical and subclinical hypothyroidism in pregnancy. Cochrane Database Syst Rev 2010:CD007752.

MacFarquhar JK, et al. Acute selenium toxicity associated with a dietary supplement. Arch Intern Med 2010; 170:256-61.

Sieja K, Talerczyk M. Selenium as an element in the treatment of ovarian cancer in women receiving chemotherapy. Gynecol Oncol 2004; 93:320-7.

Vernie LN, et al. Cisplatin-induced changes of selenium levels and glutathione peroxidase activities in blood of testis tumor patients. Cancer Lett 1988; 40:83-91.

Hu YJ, et al. The protective role of selenium on the toxicity of cisplatin-contained chemotherapy regimen in cancer patients. Biol Trace Elem Res 1997; 56:331-41

Dennert G, Horneber M. Selenium for alleviating the side effects of chemotherapy, radiotherapy and surgery in cancer patients. Cochrane Database Syst Rev 2006:CD005037

U.S. Department of Agriculture, U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2010. 7th Edition. Washington, DC; 2010

Rayman MP, Infante HG, Sargent M. Food-chain selenium and human health: spotlight on speciation. Br J Nutr 2008; 100: 238-53.

Dietary supplement fact sheet: Selenium. (accessed 01/10/2012).

Selenium. In: FAO & WHO: Human vitamin and mineral requirements. Report of a joint FAO/WHO expert consultation, Bangkok, Thailand. 2002. (accessed 01/10/2012).

National Cancer Institute: Antioxidants and Cancer Prevention: Fact Sheet (last access 29/06/2013).

Arnaud J, et al. Serum selenium determinants in French adults: the SU.VI.M.AX study. Br J Nutr 2006; 95(2): 313-20.

Burri J, Haldimann M, Dudler V. Selenium status of the Swiss population: Assessment and change over a decade. J Trace Elem Med Biol 2008; 22(2): 112-9.

Klapcinska B, et al. Selenium levels in blood of upper silesian population: evidence of suboptimal selenium in a significant percentage of the population. Biol Trace Elem Res 2005; 108(1-3): 1-16.

Vinceti M, et al. The epidemiology of selenium & human cancer. Tumori 2000; 86(2):105-18.

Rayman MP. The use of high-selenium yeast to raise selenium status: how does it measure up? Br J Nutr 2004; 92(4): 557-73.

WHO 2004: Joint FAO/WHO Expert Consultation on Human Vitamin and Mineral Requirements (1998): Bangkok T. Vitamin and mineral requirements in human nutrition: report of a joint FAO/WHO expert consultation, Bangkok, Thailand, 21-30 September 1998. 2004.

Rayman, MP: Selenium and human health. Lancet 2012; 379: 1256–68.

Fairweather-Tait SJ, et al: Selenium in Human Health and Disease. Antioxidants & Redox Signalling 2011; 14: 1337-1383

Lee JH, et al: A novel activation-induced suicidal degradation mechanism for Akt by selenium. Int J Mol Med. 2008; 21: 91–97.

Li Z, Shi K, et al: ROS leads to MnSOD upregulation through ERK2 translocation and p53 activation in selenite-induced apoptosis of NB4 cells. FEBS Lett. 2010; 584(11): 2291-7.

Dennert G, et al. Selenium for preventing cancer. Cochrane Database Syst Rev 2011; 11(5): CD005195. doi: 10.1002/14651858.CD005195.pub2

Lee, EH, et al: Effects of selenium supplements on cancer prevention: Meta-analysis of randomized controlled trials. Nutr Cancer 2011; 63: 1185-1195.

Dreno B, et al: Effect of selenium intake on the prevention of cutaneous epithelial lesions in organ transplant recipients. Eur J Dermatol 2007; 17: 140-145.

Li H, Li HQ, et al: An intervention study to prevent gastric cancer by micro-selenium and large dose of allitridum. Chin Med J 2004; 117: 1155-1160.

Yu SY, et al: A preliminary report on the intervention trials of primary liver cancer in high-risk populations with nutritional supplementation of selenium in China. Biol Trace Elem Res 1991; 29: 289-294.

Reid ME, et al. The nutritional prevention of cancer: 400 mcg per day selenium treatment. Nutr Cancer 2008; 60(2): 155-63.

Lippman SM, et al: Effect of Selenium & Vitamin E on Risk of Prostate Cancer and Other Cancers: The Selenium & Vitamin E Cancer Prevention Trial (SELECT). JAMA 2009; 301(1):39-51

Sutter ME, Thomas JD, Brown J, Morgan B. Selenium toxicity: a case of selenosis caused by a nutritional supplement. Ann Intern Med 2008; 148(12): 970-1.

Stranges S, et al: Effects of Long-Term Selenium Supplementation on the Incidence of Type 2 Diabetes: A Randomized Trial. Ann Intern Med 2007; 147:217-223.

See KA, Lavercombe PS, Dillon J, Ginsberg R. Accidental death from acute selenium poisoning. Med J Aust 2006; 185(7): 388-9.

Sandström B: Micronutrient interactions: effects on absorption and bioavailability. Br J Nutr 2001; 85: S181-S185.

These statements have not been evaluated by the Food and Drug Administration.

The information provided in this brochure is for informational purposes only and is not intended as a substitute for advice from your physician or other health care professional You should not use the information in this brochure for diagnosis or treatment of any health problem or for prescription of any medication or other treatment. You should consult with a healthcare professional before starting any diet, exercise or supplementation program, before taking any medication, or if you have or suspect you might have a health problem.