Thyroid Health supplies a blend of vitamins and herbs specifically designed to promote the health of the thyroid to support growth, metabolism, energy, and cognitive function. An optimally functioning thyroid is essential to a healthy body.

Included in this formula are vitamin B12, iodine, minerals (magnesium, zinc, selenium, copper, manganese, and molybdenum), L-Tyrosine, and herbal ingredients (schisandra, coleus forskohlii, ashwagandha, bladderwrack, and cayenne pepper).

 

Hyper- and hypo-thyroidisms are debilitating conditions which results from over- or under-active thyroids. Thyroid Health can help prevent these harmful conditions by ensuring the proper functioning of the thyroid. For more information and research citations on each ingredient, please read below.

Background:

The thyroid is one of the most important glands in the body.  The hormones secreted by the thyroid gland are responsible for regulating how fast the body uses energy, synthesizes proteins, and reacts to other hormones.  They are also important for metabolism and growth, especially in children.  Hypothyroidism, an underactive thyroid, and hyperthyroidism, an overactive thyroid, are the two most common thyroid complications. 

Symptoms of hypothyroidism are varied, but may include increased sensitivity to cold, fatigue, constipation, weight gain, depression, brittle hair and nails, abnormal menstruation, and speech impairment. 

Symptoms of hyperthyroidism may include weight loss, ravenous appetite, fatigue, weakness, intolerance to heat, sweating, loss of libido, nausea, vomiting, and diarrhea. 


The Ingredients of Thyroid Health:

 

VITAMIN B12 may be used to increase energy and prevent fatigue.  B-12 works by increasing the amount of hemoglobin in the blood. 

Hemoglobin is the substance which carries oxygen from the lungs to the muscles and other organs in the body. 

By increasing the body’s ability to transport oxygen, vitamin B-12 helps the body use energy more efficiently.

According to the National Institutes of Health and the Mayo Clinic, other uses for vitamin B-12 include treatment for:

• Vitamin deficiency
• Anemia
• Alzheimer’s Disease
• Angioplasty
• Breast Cancer
• Fatigue
• High cholesterol
• Shaky leg syndrome
• Sickle Cell Disease
• Cardiovascular disease

Click here to see a report from the National Institutes of Health. According to this report, B-12 may play a role in treatments for Alzheimer's disease and breast cancer.

 

 

IODINE is essential for regulating the thyroid gland.  The National Institutes of Health recognizes iodine as a disinfectant, as protection from radiation, and for prevention of goiter, a disease of the thyroid.  Supplements may help improve cognitive function, since iodine controls the thyroid.  The thyroid gland controls the body’s use of energy, response to other hormones, and production of proteins.  Thyroid hormones are also necessary for proper brain function.  According to the National Institutes of Health, iodine has even displayed some anti-carcinogenic effects in the laboratory.


MAGNESIUM allows the body to store potassium which would otherwise be excreted in the urine.  This is especially important to patients with high blood pressure, who are given diuretics as part of the initial treatment.  Patients with hypertension often show magnesium depletion as well.  Magnesium is used in treatments for congestive heart failure, angina, cardiac arrhythmias, and cardiovascular disease (National Institutes of Health – Office of Dietary Supplements). 

The University of Maryland Medical Center reports that “the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends adequate amounts of potassium in the diet, along with other measures such as dietary calcium and weight loss, to prevent the development of high blood pressure. Similarly, the Dietary Approaches to Stop Hypertension (DASH) diet emphasizes eating foods rich in fruits, vegetables, and low- or non-fat dairy products to provide high intake of potassium, as well as magnesium and calcium.”


SELENIUM is an element required in only small amounts in the diet.  It is important for forming selenoproteins, powerful natural anti-oxidants responsible for protecting cell membranes from free radicals, toxins produced by the body.  In addition, selenium is used to create a unique amino acid, selenomethionine. 

People with a selenium deficiency show a weakened immune system and are at risk for hyperthyroidism, a form of heart disease.  According to the National Institutes of Health, moreover, some studies suggest that there may be a connection between rheumatoid arthritis and selenium deficiency.  Selenium and vitamin E, taken in conjunction, are being researched for their anticarcinogenic properties.


MANGANESE exhibits antioxidant properties, but it is important also for bone growth and cartilage synthesis.  Manganese is required for the body to properly use Vitamin C.  By activating many important enzymes, manganese detoxifies the body. 

In addition, manganese is used by the nervous system.  Manganese is needed for the activation of dopamine, an important neurotransmitter.  Moreover, manganese stimulates the production of choline in the liver, and acetyl choline combines with ATP to create adrenaline and noradrenaline, two chemicals which help the body deal with stress.  Additonal manganese may promote the optimal functioning of these processes. See here for research and citations.


ZINC, like many other minerals, is important for growth.  Zinc also plays a role in healing wounds, synthesizing proteins, and in boosting the immune system.   Taking zinc supplements while fighting a common cold may decrease recovery time.  Zinc is essential for normal visual signal transmission in the retina. Zinc is part of many of the enzymes involved in vitamin A-dependent light reactions in the rod cells. Moreover, zinc is an essential part of the process that removes potentially dangerous superoxide radicals in the visual cells, the lens, and other tissues.


MOLYBDENUM may help prevent the decay of tooth enamel.  It is present in high concentrations in the liver and kidneys, suggesting that it may have an important function there.  It is essential for the synthesis of several enzymes which are responsible for the metabolism of sulfur-containing amino acids, creation of blood anti-oxidants, and the metabolism of drugs and toxins.


COPPER may have some anti-cancer properties.  It is also a folk remedy for arthritis.  Preliminary research suggests, moreover, that copper may provide benefits to the immune system. Copper is a trace element essential to nutrition, but toxic in high quantities.

Deficiency may occur in individuals with metabolic disorders or in third world countries where diets are poor.  Symptoms of copper deficiency include decreased immune function, and in people whose deficiency is very minimal, copper supplementation has been shown to boost the body’s ability to fight infection.  Maintaining a healthy immune system is an important part of having healthy skin.


TYROSINE is a nonessential amino acid that is often recommended for weight loss, depression, and Parkinson’s disease.  Tyrosine is used to synthesize several essential neurotransmitters, including epinephrine, norepinephrine, serotonin, and dopamine.  It also plays a role in synthesizing the thyroid hormones, thyroxine and triiodothyronine, and in producing melanin in the skin and hair. 

Importantly, tyrosine exhibits some antioxidant effects. It has the ability to destroy excess free radicals caused by smoking, radiation, or exposure to toxins.  In alternative medicine, tyrosine is prescribed to relieve stress because it qualifies as an adaptogen.  An adaptogen is a sub-stance which helps the body to cope with stressful conditions by promoting normal, healthy mental function.  Tyrosine’s adaptogen qualities may be related to its ability to regulate neurotransmitters which affect mood and anxiety. 


SCHISANDRA acts in the liver to cleanse and purify the system.  In traditional Chinese herbal medicine, schisandra  is used as a remedy for resisting infections, increasing skin health, and combating insomnia, coughing, and thirst.


COLEUS FORSKOHLII is a source of forskolin, a natural substance which has the ability to help cells respond to hormones.  This herb may support the body’s ability to use progesterone.  Forskolin is a vital compound to the health of cells.  The most recent research indicates that forskolin may also be used to treat urinary tract infections more effectively than current methods.


ASWAGANDHA, also called Indian ginseng, is used to boost energy, improve mental capacity, and increase stamina, vitality, and sexual energy.  It has been used in traditional Indian medicine for thousands of years as a “cure-all.”  It is not a direct relative of the Asian and American ginseng plants, but its uses are so similar that the name of the more well-known Chinese plant has been commonly adopted.  Its traditional name is Ashwagandha. 

Recent research has discovered the chemical processes behind the traditional uses of Indian Ginseng.  The root of the plant contains flavonoids, saponins, and substances called withanolides.  Flavonoids are antioxidant, anti-allergenic, and anti-inflammatory agents which are beneficial to overall good health.  Saponins are plant steroids found in all plants and which boost the immune response.  Withanolides provide the specific benefits of Indian Ginseng by reacting with neurotransmitters in the brain and increasing the concentration of acetylcholine, a chemical neurotransmitter.  Together these substances promote a healthy environment in the nervous system and an optimal use of energy.

Although it is often called “Indian ginseng”, Ashwagandha is not related to panax ginseng (“Chinese ginseng”), an unrelated species of herb.  Ashwagandha acquired the name Indian Ginseng because it is used in the same way as Chinese ginseng, and it exhibits similar health benefits.

The “cure-all” reputation of ginseng derives from its cumulative effect on the body – it assists the body to adapt to abnormal stresses such as fatigue and disease.  For this reason it is labeled an adaptogen – a substance which helps restore balance and normalize the body’s functioning.  Indian ginseng is an ancient means of maintaining good overall health.


BLADDERWRACK, a brown seaweed, may help slow the body’s absorption of carbohydrates from foods.  In clinical trials, bladderwrack has been shown to decrease the activity of alpha-amylase and alpha-glucosidae, two of the most important enzymes for carbohydrate metabolism.  By slowing the activity of these enzymes, bladderwrack prevents carbohydrates from being absorbed too quickly.  The more efficient metabolism of carbohydrates which results from bladderwrack supplementation may help manage weight loss when combined with exercise and a healthy diet. Bladderwrack is also a good source of iodine.


CAYENNE is a versatile herb originally used by Native Americans as a pain reliever.  Two of its effects suggest that it may be able to contribute to weight loss.  First, it temporarily increases the body’s production of heat (UMM).  Second, it affects the body’s breaking down of carbohydrates (UMM).  By allowing for a more efficient metabolism, cayenne may help manage body weight.


RESEARCH AND MORE INFORMATION:

VITAMIN B12 - from the National Institutes of Health:

About Vitamin B12 Deficiency:

Results of two national surveys, the National Health and Nutrition Examination Survey (NHANES III-1988-94) and the Continuing Survey of Food Intakes by Individuals (CSFII 1994-96) found that most children and adults in the United States (US) consume recommended amounts of vitamin B12. A deficiency may still occur as a result of an inability to absorb vitamin B12 from food and in strict vegetarians who do not consume any foods that come from animals. As a general rule, most individuals who develop a vitamin B12 deficiency have an underlying stomach or intestinal disorder that limits the absorption of vitamin B12. Sometimes the only symptom of these intestinal disorders is subtly reduced cognitive function resulting from early vitamin B12 deficiency. Anemia and dementia follow later.

Signs, symptoms, and health problems associated with vitamin B12 deficiency:

• Characteristic signs, symptoms, and health problems associated with vitamin B12 deficiency include anemia, fatigue, weakness, constipation, loss of appetite, and weight loss. Deficiency also can lead to neurological changes such as numbness and tingling in the hands and feet. Additional symptoms of vitamin B12 deficiency are difficulty in maintaining balance, depression, confusion, dementia, poor memory, and soreness of the mouth or tongue.
• Signs of vitamin B12 deficiency in infancy include failure to thrive, movement disorders, delayed development, and megaloblastic anemia.

Special Medical Conditions Requiring B12 Supplementation:

Individuals with pernicious anemia:

Anemia is a condition that occurs when there is insufficient hemoglobin in red blood cells to carry oxygen to cells and tissues. Common signs and symptoms of anemia include fatigue and weakness. Anemia can result from a variety of medical problems, including deficiencies of vitamin B12, vitamin B6, folate and iron. Pernicious anemia is the name given more than a century ago to describe the then-fatal vitamin B12 deficiency anemia that results from severe gastric atrophy, a condition that prevents gastric cells from secreting intrinsic factor. Intrinsic factor is a substance normally present in the stomach. Vitamin B12 must bind with intrinsic factor before it can be absorbed and used by your body. An absence of intrinsic factor prevents normal absorption of vitamin B12 and results in pernicious anemia.

Most individuals with pernicious anemia need parenteral (deep subcutaneous) injections (shots) of vitamin B12 as initial therapy to replenish depleted body stores of vitamin B12. Vitamin B12 body stores can then be managed by a daily oral supplement of vitamin B12. A physician will manage the treatment required to maintain the vitamin B12 status of individuals with pernicious anemia.

Individuals with gastrointestinal disorders:
Individuals with stomach and small intestine disorders may be unable to absorb enough vitamin B12 from food to maintain healthy body stores. Intestinal disorders that may result in malabsorption of vitamin B12 include:

Sprue, often referred to as celiac disease (CD), is a genetic disorder. People with CD are intolerant to a protein called gluten. In CD, gluten can trigger damage to the small intestines, where most nutrient absorption occurs. People with CD often experience nutrient malabsorption. They must follow a gluten-free diet to avoid malabsorption and other symptoms of CD.

Crohn's disease is an inflammatory bowel disease that affects the small intestines. People with Crohn's disease often experience diarrhea and nutrient malabsorption.
Surgical procedures in the gastrointestinal tract, such as surgery to remove all or part of the stomach, often result in a loss of cells that secrete hydrochloric acid and intrinsic factor. Surgical removal of the distal ileum, a section of the intestines, also can result in the inability to absorb vitamin B12. Anyone who has had either of these surgeries usually requires lifelong vitamin B12 supplements to prevent a deficiency. These individuals would be under the routine care of a physician, who would periodically evaluate vitamin B12 status and recommend appropriate treatment.

Older adults:
Hydrochloric acid helps release vitamin B12 from the protein in food. This must occur before vitamin B12 binds with intrinsic factor and is absorbed in your intestines. Atrophic gastritis, which is an inflammation of the stomach, decreases the secretion of gastric juices, including hydrochloric acid. Less hydrochloric acid decreases the amount of vitamin B12 separated from proteins in foods and can result in poor absorption of vitamin B12. Decreased hydrochloric acid secretion also results in growth of normal bacteria in the small intestines.

The bacteria may take up vitamin B12 for their own use, further contributing to a vitamin B12 deficiency. Up to 30 percent of adults aged 50 years and older may have atrophic gastritis, an increased growth of intestinal bacteria, and be unable to normally absorb vitamin B12 in food. They are, however, able to absorb the synthetic vitamin B12 added to fortified foods and dietary supplements. Vitamin supplements and fortified foods may be the best sources of vitamin B12 for adults older than age 50 years.

Researchers have long been interested in the potential connection between vitamin B12 deficiency and dementia. A recent review examined correlations between cognitive skills, homocysteine levels, and blood levels of folate, vitamin B12 and vitamin B6. The authors suggested that vitamin B12 deficiency may decrease levels of substances needed for the metabolism of neurotransmitters. Neurotransmitters are chemicals that transmit nerve signals. Reduced levels of neurotransmitters may result in cognitive impairment. In 142 individuals considered at risk for dementia, researchers found that a daily supplement providing 2 milligrams (mg) folic acid and 1 mg vitamin B12, taken for 12 weeks, lowered homocysteine levels by 30%.

They also demonstrated that cognitive impairment was significantly associated with elevated plasma total homocysteine. However, the decrease in homocysteine levels seen with the use of vitamin supplements did not improve cognition. It is too soon to make any recommendations, but is an intriguing area of research.


Vegetarians:
The popularity of vegetarian diets has risen along with an interest in avoiding meat and meat products for environmental, philosophical, and health reasons. However, the term vegetarianism is subject to a wide range of interpretations. Some people consider themselves to be vegetarian when they avoid red meat. Others believe that vegetarianism requires avoidance of all products that come from animals, including meat, poultry, fish, eggs, and dairy foods. The most commonly described forms of vegetarianism include:

• "lacto-ovo vegetarians", who avoid products that come from meat, poultry, and fish but consume eggs and dairy foods; "strict vegetarians", who avoid meat, poultry, fish, eggs, and dairy foods; and
• "vegans", who avoid meat, poultry, fish, eggs, and dairy foods and also do not use products that come from animals such as honey, leather, fur, silk, and wool.

Strict vegetarians and vegans are at greater risk of developing vitamin B12 deficiency than lacto-ovo vegetarians and nonvegetarians because natural food sources of vitamin B12 are limited to foods that come from animals. Fortified cereals are one of the few sources of vitamin B12 from plants, and are an important dietary source of vitamin B12 for strict vegetarians and vegans. Strict vegetarians and vegans who do not consume foods that come from plants that are fortified with vitamin B12 need to consider taking a dietary supplement that contains vitamin B12 and should discuss the need for vitamin B12 supplements with their physician.  
When adults adopt a strict vegetarian diet, deficiency symptoms can be slow to appear. It may take years to deplete normal body stores of vitamin B12. However, breast-fed infants of women who follow strict vegetarian diets have very limited reserves of vitamin B12 and can develop a vitamin B12 deficiency within months.

This is of particular concern because undetected and untreated vitamin B12 deficiency in infants can result in permanent neurologic damage. Consequences of such neurologic damage are severe and can be irreversible. There are many case reports in the literature of infants and children who suffered consequences of vitamin B12 deficiency. It is very important for mothers who follow a strict vegetarian diet to consult with a pediatrician regarding appropriate use of vitamin B12 supplements for their infants and children.


Uses for Vitamin B12 based on scientific evidence:

Vitamin B12 deficiency:

Studies have shown that a deficiency of vitamin B12 can lead to abnormal neurologic and psychiatric symptoms. These symptoms may include: ataxia (shaky movements and unsteady gait), muscle weakness, spasticity, incontinence, hypotension, vision problems, dementia, psychoses, and mood disturbances. Researchers report that these symptoms may occur when vitamin B12 levels are just slightly lower than normal and are considerably above the levels normally associated with anemia.

People at risk for vitamin B12 deficiency include strict vegetarians, elderly people, and people with increased vitamin B12 requirements associated with pregnancy, thyrotoxicosis, hemolytic anemia, hemorrhage, malignancy, liver or kidney disease. Administering vitamin B12 orally, intramuscularly, or intranasally is effective for preventing and treating dietary vitamin B12 deficiency. An oral dose of 100-250 micrograms/day is usually adequate although patients with absorption difficulties may need 1000 micrograms/day of vitamin B12. Oral preparations should not be used in patients with diarrhea, vomiting, severe neurologic involvement, or in patients likely to be noncompliant to therapy.


Megaloblastic anemia:

Vitamin B12 deficiency is a cause of megaloblastic anemia. In this type of anemia, red blood cells are larger than normal, and the ratio of nucleus size to cell cytoplasm is increased. There are other potential causes of megaloblastic anemia, including folate deficiency or various inborn metabolic disorders. If the cause is B12 deficiency, then treatment with B12 is the standard approach. Patients with anemia should be evaluated by a physician in order to diagnose and address the underlying cause.


Pernicious anemia :

Pernicious anemia (blood abnormality) is a form of anemia that occurs when there is an absence of intrinsic factor, a substance normally present in the stomach. Vitamin B12 binds with intrinsic factor before it is absorbed and used by the body. An absence of intrinsic factor prevents normal absorption of B12 and may result in pernicious anemia. Pernicious anemia treatment is usually lifelong supplemental vitamin B12 given either intramuscularly, intranasally, or by mouth.


Alzheimer's disease :

Some patients diagnosed with Alzheimer's disease have been found to have abnormally low vitamin B12 levels in their blood. However, vitamin B12 deficiency itself often causes disorientation and confusion and thus mimics some of the prominent symptoms of Alzheimer's disease. Well designed clinical trials are needed before a recommendation can be made.


Angioplasty:

Some evidence suggests that folic acid 1mg plus vitamin B12 400mcg and pyridoxine 10mg daily can decrease the rate of restenosis in patients treated with balloon angioplasty. But this combination does not seem to be as effective for reducing restenosis in patients after coronary stenting. An intravenous loading dose of folic acid, vitamin B6 and vitamin B12 followed by oral administration of folic acid 1.2mg plus vitamin B6 48mg and vitamin B12 60mcg taken daily after coronary stenting also does not seem to reduce restenosis and might actually increase restenosis. Due to the lack of evidence of benefit and potential for harm, this combination of vitamins should not be recommended for patients receiving coronary stents.


Breast cancer:

Researchers at Johns Hopkins University report that women with breast cancer tend to have lower vitamin B12 levels in their blood serum than do women without breast cancer. In a subsequent review of these findings, it was hypothesized that vitamin B12 deficiency may lead to breast cancer because it could result in less folate being available to ensure proper DNA replication and repair. Higher dietary folate intake is associated with a reduced risk of breast cancer. The risk may be further reduced in women who also consume high amounts of dietary vitamin B12 in combination with dietary pyridoxine (vitamin B6) and methionine. However, there is no evidence that dietary vitamin B12 alone reduces the risk of breast cancer.


Fatigue:

There is some evidence that intramuscular injections of 5mg of vitamin B12 given twice per week might improve the general well being and happiness of patients complaining of tiredness or fatigue. However, fatigue has many potential causes. Well designed clinical trials are needed before a recommendation can be made.


High cholesterol:

Some evidence suggests that 7.5mcg of vitamin B12 in combination with 5 grams of fish oil might be superior to fish oil alone when used daily to reduce total serum cholesterol and triglycerides. Well designed clinical trials of vitamin B12 supplementation alone are needed before a conclusion can be drawn.


Shaky-leg syndrome:

Preliminary clinical reports show that cyanocobalamin may help relieve tremor associated with shaky-leg syndrome. Further research is needed to confirm these results.


Sickle cell disease:

One study suggests that a practical daily combination may be 1mg folic acid, 6mcg vitamin B12, and 6mg vitamin B6. This combination may be a simple and relatively inexpensive way to reduce these patients' inherently high risk of endothelial damage. Further research is needed to confirm these results.


Vitamin B12 may have a connection with cardiovascular disease:

Cardiovascular disease is the most common cause of death in industrialized countries such as the United States, and is on the rise in developing countries. The National Heart, Lung, and Blood Institute of the National Institutes of Health has identified many risk factors for cardiovascular disease, including an elevated LDL-cholesterol level, high blood pressure, a low HDL-cholesterol level, obesity, and diabetes. In recent years, researchers have identified another risk factor for cardiovascular disease: an elevated homocysteine level. Homocysteine is an amino acid normally found in blood, but elevated levels have been linked with coronary heart disease and stroke.

Elevated homocysteine levels may impair endothelial vasomotor function, which determines how easily blood flows through blood vessels. High levels of homocysteine also may damage coronary arteries and make it easier for blood clotting cells called platelets to clump together and form a clot, which may lead to a heart attack.

Vitamin B12, folate, and vitamin B6 are involved in homocysteine metabolism. In fact, a deficiency of vitamin B12, folate, or vitamin B6 may increase blood levels of homocysteine. Recent studies found that vitamin B12 and folic acid supplements decreased homocysteine levels in subjects with vascular disease and in young adult women. The most significant drop in homocysteine level was seen when folic acid was taken alone. A significant decrease in homocysteine levels also occurred in older men and women who took a multivitamin/ multimineral supplement for 8 weeks. The supplement taken provided 100% of Daily Values (DVs) for nutrients in the supplement.


IODINE - From the National Institutes of Health:

 

Background
Iodine is an element (atomic number 53), which is required by humans for the synthesis of thyroid hormones (triiodothyronine/T3 and thyroxine/T4).

Chronic iodine deficiency can lead to numerous health problems in children and adults, including thyroid gland dysfunction (including goiter) and various neurologic, gastrointestinal, and skin abnormalities. Iodine deficiency in pregnant or nursing mothers can lead to significant neurocognitive deficits in their infants. "Cretinism" or severe mental retardation is a rare outcome of severe iodine deficiency during early development. Growth stunting, apathy, impaired movement, or speech/hearing problems may occur. Many individuals living in developing countries may be at risk of iodine deficiency and its complications, and iodine deficiency is considered to be a preventable cause of mental retardation.

Iodine deficiency is rare in industrialized countries such as the United States, due to enrichment of table salt and cattle feed with iodine. But deficiency is common in developing countries, where supplementation may be considered.

Humans obtain iodine from their diets. The amount of iodine in food or water depends upon the amount of iodine in the local soil. Areas with mountainous (glacier) water or heavy rainfall tend to be low in iodine content, increasing the risk of iodine deficiency.

This review does not discuss medical uses of radioactive iodine or iodine contrast agents used for imaging studies such as computerized tomography (CT scanning).

Synonyms
Atomic number 53, Betadine®, cadexomer iodine, I, Iodin, iodine-125, iodine-131, iodized poppy seed oil, iodized salt, iodothyronine, iodotyrosine, KI, Licartin, Lipiodol®, Lugol solution, potassium iodide (KI), polyvinylpyrrolidone-iodine, povidone-iodine, PVP-I, radioiodine, SKI, strong iodine, tincture of iodine.

Note: This review does not discuss medical uses of radioactive iodine or iodine contrast agents used for imaging studies such as computerized tomography (CT scanning).

Evidence
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence Grade*

Goiter prevention
Iodine deficiency is one of the causes of goiter (hypertrophy of the thyroid gland as it tries to make more thyroid hormone in the absence of iodine). Physically, goiter appears as an abnormal enlargement of the thyroid gland in the neck. Other causes of goiter include autoimmune thyroiditis, excess iodine, other hormonal disorders, radiation exposure, infectious causes, or inborn errors of metabolism. Although goiter due to low iodine intake is rare in developed countries, it may occur in regions with endemic low iodine levels. To avoid iodine deficiency in the United States, table salt is enriched with iodine ("iodized" salt), and iodine is added to cattle feed and used as a dough conditioner. Iodine supplementation is generally not recommended in developed countries where sufficient iodine intake is common, and excess iodine can actually cause medical complications (including goiter).Iodine supplementation should be considered in cases of known iodine deficiency, and should be administered with medical supervision if possible. Notably, the treatment of goiter usually involves administration of thyroid hormone, most commonly levothyroxine sodium (Synthroid®, Levoxyl®, Levothroid®). Iodine generally does not play a role in the acute management of this condition.  A

Iodine deficiency
In regions with low iodine intake or cases of known deficiency, iodine enrichment of foods or supplementation should be considered. To avoid iodine deficiency in the United States, table salt is enriched with iodine ("iodized" salt), and iodine is added to cattle feed and used as a dough conditioner. Iodine deficiency is uncommon in developed countries, but is common in other parts of the world. When considering iodine enrichment or supplementation, supervision by medical personnel or public health officials is recommended due to the potential complications involved with iodine replacement in the setting of previous deprivation, particularly if considering supplementation in pregnant women or children.  A

Radiation emergency (potassium iodide thyroid protection)
Potassium iodide (KI) can be taken in the setting of radiation exposure in order to reduce levels of radioactive iodine uptake by the thyroid, thus reducing the risk of later development of thyroid cancer. It is important to note that KI does not provide immediate protection from radiation damage, and does not have protective effects against other complications of radiation exposure. KI can serve as a part of a general strategy in cases of radiation emergencies, in conjunction with shelter and control of foodstuffs. Many radiation emergency kits include KI.  A

Skin disinfectant/sterilization
Iodine is commonly used in topical disinfectant preparations for cleaning wounds, sterilizing skin before surgical/invasive procedures, or sterilizing catheter entry sites. Betadine solution, for example, contains povidone-iodine. Other topical disinfectants include alcohol and antibiotics, and iodine is sometimes used in combination with these. Commercially prepared iodine products are recommended in order to assure appropriate concentrations.  A

Water purification
Iodine can be used as an antimicrobial agent for the emergency purification of water. Tablets and solutions are commercially available. Effects generally occur within 15 minutes.  A

Bacterial conjunctivitis
Povidone-iodine solutions have been used in the management of childhood bacterial conjunctivitis, and may be as effective as other anti-bacterial solutions such as neomycin-polymyxin B-gramicidin. This is not an effective treatment for viral conjunctivitis. Medical supervision is recommended.  B

Graves disease (adjunct iodine/iodides)
Graves disease is an immune-mediated disorder that causes hyperthyroidism. Thyroid-stimulating immunoglobulins bind to the thyroid stimulating hormone (TSH) receptor and mimic the action of thyroid TSH, and stimulate thyroid growth and thyroid hormone overproduction. Standard treatments for Graves disease target the thyroid gland (rather than the source of the disorder), and include antithyroid drugs such as propylthiouracil or methimazole, radioactive iodine to ablate (destroy) thyroid cells, or surgery to remove thyroid tissue. Beta-blocker drugs may be used to control symptoms. Iodide preparations can be used to suppress thyroid hormone release from the thyroid, such as strong iodine solution (Lugol solution), potassium iodide (SSKI), and iodinated radiographic contrast agents (sodium ipodate). Patients undergoing thyroid surgery are commonly treated preoperatively with antithyroid drugs to achieve a euthyroid state, then SSKI.  B

Hearing loss (iodine deficiency)
Auditory disturbances may be present in iodine deficient children, and continuous iodine supplementation may improve the auditory thresholds.  B

Ocular surgery infection prevention / cataract surgery antisepsis
Topical iodine solutions such as povidone-iodine are used preoperatively to sterilize prior to ophthalmologic procedures. For example, povidone-iodine solution has been studied and used preoperatively for cataract surgery antisepsis.  B

Ophthalmia neonatorum prevention
"Ophthalmia neonatorum" is defined as conjunctivitis with eye discharge that occurs during the first month of life. Various bacteria can cause this condition, including gonococcus and Chlamydia trachomatis . Several agents have been used as drops in the eyes to prevent this condition in infants, including erythromycin, silver nitrate, gentamicin, and povidone-iodine. Tetracycline and penicillin drops have also been used. Although this condition is now uncommon in industrialized nations, it remains a problem in the developing world with an incidence as high as 20-30% and cases of blindness reported in Africa each year.Povidone-iodine ophthalmic solution appears to have broad-spectrum activity against bacteria, and is less expensive than many antibiotics. It therefore may be a cost-effective option in some populations.  B

Oral mucositis
There is limited research to suggest that iodine mouth rinses may decrease the severity of mucositis in the mouth related to cancer chemotherapy or radiation therapy. The management of mucositis should be discussed with the cancer care team.  B

Thyrotoxicosis / thyroid storm (adjunct iodides)
Hyperthyroid crisis (thyroid storm) is a medical emergency caused by excessive release of thyroid hormones into the circulation. Initial management of this condition involves inhibition of thyroid function with thioamide drugs such as propylthiouracil or methimazole. Iodides (such as potassium iodide) can then be administered to block the release of thyroid hormone, but should only be given an hour after thioamides to assure that the iodide is not used by the thyroid to make more thyroid hormone and worsen symptoms. Caution is warranted, because iodide preparations carry a risk of causing serum sickness. Iodides should not be used for long-term treatment of thyrotoxicosis.  B

Bladder irrigation
Povidone-iodine bladder irrigation has been suggested prior to catheter removal, or prior to prostatectomy surgery, to reduce the risk of infection. There is limited research in this area.  C

Bowel irrigation
Povidone-iodine irrigation before large bowel resection has been suggested as a sterilization technique.  C

Cancer
The potential role of non-radioactive iodine in cancer care remains unknown. Antioxidant and anti-tumor effects have been proposed based on laboratory research. In contrast, some scientists have asserted that tumors may uptake more iodine than normal tissues. It has been suggested that high rates of gastric (stomach) cancer or low rates of breast cancer in coastal Japan may be due to high iodine intake, although this has not been demonstrated scientifically. Povidone-iodine solutions have been used as a part of alternative cancer regimens, such as the Hoxsey formula. Preliminary study has also indicated povidone-iodone solution as a potential rectal washout for rectal cancer. Overall, no clear conclusion can be drawn based on the currently available evidence.  C

Cognitive function
Iodine is required for the production of thyroid hormones, which are necessary for normal brain development and cognition. One study showed that oral iodized oil significantly improved performance on cognitive tests in 10-12 year-old school children. Further study is needed to confirm these results.  C

Corpus vitreous degeneration
Topical administration of iodine eye drops may reduce corpus vitreous degeneration. Further study is needed to confirm these results.  C

Goiter treatment

Iodine deficiency can cause goiter (hypertrophy of the thyroid gland). Other causes of goiter should be considered in patients with this condition, such as autoimmune thyroiditis, excess iodine, other hormonal disorders, radiation exposure, infectious causes, or inborn errors of metabolism. Although goiter due to low iodine intake is rare in developed countries, it may occur in regions with endemic low iodine levels.Initial management of goiter should involve a medical evaluation to identify the underlying cause, and assessment of levels of thyroid hormones in the body. Treatment usually involves administration of thyroid hormone, most commonly levothyroxine sodium (Synthroid, Levoxyl, Levothroid). Iodine plays a role in goiter prevention, but not in acute management of this condition. Iodine deficiency should be corrected if found, with supplementation.  C

Lymphedema (filarial)
Footcare with betadine may help in the management of filarial lymphoedema.  C

Molluscum contagiosum
Povidone-iodine has been suggested as a topical treatment for molluscum. There is limited research in this area.  C

Oral intubation
Gargling with povidone-iodine before oral intubation reduces the transport of bacteria into the trachea.  C

Pelvic infection
Vaginal douching with aqueous povidone iodine followed by normal saline irrigation immediately before oocyte retrieval seems effective in preventing the pelvic infection without compromising the outcome of in vitro fertilization treatment.  C

Periodontitis / gingivitis
Povidone-iodine mouthwash has been suggested to reduce mouth flora in the setting of periodontitis or around oral surgery. Evidence in this area is not conclusive.  C

Pneumonia
Based on one prospective randomized study regular oropharyngeal application of povidone-iodine may decrease the prevalence of ventilator-associated pneumonia in patients with severe head trauma. Evidence in this area is not conclusive.  C

Postcesarean endometritis
Preoperative vaginal scrub with povidone-iodine decreases the incidence of postcesarean endometritis. This intervention does not seem to decrease the overall risk of postoperative fever or wound infection.  C

Renal Pelvic Instillation Sclerotherapy (RPIS)
Povidone iodine 0.2% has been shown to be as effective for RPIS as 1% silver nitrate.  C

Wound healing
It is not clear if healing of wounds or skin ulcers is improved with the application of topical iodine solutions. Iodine solutions may assist with sterilization as a part of a larger approach to the healing process.  C

Visual outcomes in corneal ulceration
The addition of povidone-iodine to standard antibiotic therapy did not improve visual outcomes in corneal ulceration patients in one study.  D

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.
Grading rationale

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Anemia,Ascaris lumbricoides, burn wound healing, chronic otitis media, circulation enhancement, cutaneous sporotrichosis, dendritic keratitis, diabetic foot ulcers, energy level enhancement, fibrocystic breast disease, hookworm, hyperlipidemia,infant mortality improvement, Kashin-Beck osteoarthropathy, keratoconjuctivitis, renal impairment, respiratory congestion, thyroid adenoma,Trichuris trichiura,Schistosoma mansoni, vaginitis, venous leg ulcers, weight loss, wound infection.

Dosing
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older):

U.S. Recommended Daily Allowance (RDA): 150 micrograms daily in adults ages 18 and older (220 micrograms daily for pregnant women, 290 micrograms daily for breastfeeding women).

Tolerable Upper Intake Levels (UL): For adults ages 18 and older, 1,100 micrograms daily.
Cataract surgery antisepsis: 1% povidone-iodine solution used preoperatively. Eye drops containing 0.8% povidone-iodine solution have been used three times every five minutes prior to surgery.

Chronic suppurative otitis media: 5% povidone-iodine ear drops, three drops taken three times daily for 10 days has been used, although other approaches such as antibiotics should be considered and discussed with a supervising healthcare professional.

Goiter: In those with goiter induced by iodine deficiency, correction may not be practical, and treatment should involve thyroid hormone replacement with levothyroxine sodium (Synthroid, Levoxyl, Levothroid). If practical, iodine deficiency can be corrected, although iodine deficiency is rare in industrialized countries due to supplementation of table salt and cattle feed with iodine.

See above dosing for iodine deficiency. Other causes of goiter should also be considered, under the supervision of a licensed healthcare professional. For endemic goiter, 400 micrograms of iodine dialy as di-iodotyrosine has been used, or 150 micrograms iodine/500 micrograms iodide with levothyroxine has been used. For gestational goiter, under medical supervision, doses of 50-200 micrograms of iodide daily has been used.

Hyperthyroidism, Graves disease, thyroid storm: As an adjunct to prescription drug inhibitors of thyroid function (such as propylthiouracil or methimazole), saturated solution of potassium iodide (SSKI, PIMA) 1-5 gtt by mouth every 8 hours, or Lugol solution (8 milligrams iodide per drop) 2-6 gtt (1 milliliter) every 8 hours has been used. For thyrotoxicosis, parenteral treatment may be used, and sodium iodide 1 gram by slow intravenous drip every 8-12 hours has been given. Management should be under the supervision of a licensed healthcare professional. Lower doses may be used in pregnancy.

Iodine deficiency: Iodine deficiency is rare in industrialized countries due to supplementation of table salt and cattle feed with iodine. In areas of endemic iodine deficiency, various doses of iodine have been used as prevention or treatment, including 200 milligrams or 2 milliliters of iodized oil daily by mouth. For prolonged supplementation, a single annual intramuscular injection with 1 milliliter Lipiodol UF (480 milligrams of iodine) or 570 milligrams of oral iodine has been used. In those with goiter induced by iodine deficiency, correction may not be practical, and treatment should involve thyroid hormone replacement with levothyroxine sodium (Synthroid, Levoxyl, Levothroid).

Mouthwash: As an antibacterial mouthwash, 10-20 milliliters of povidone-iodine mouthwash has been used as a rinse and gingival sulcus irrigant. For prevention of plaque and gingivitis, mouth rinses have been used up to twice daily. For chemotherapy mucositis prevention, povidone-iodine rinses have been used up to four times daily.

Pneumonia: 20 milliliters of a 10% povidone-iodine aqueous solution, reconstituted in a 60 milliliters solution with sterile water has been used as a nasopharynx and oropharynx rinse in patients with pneumonia and head trauma.

Preoperative before thyroidectomy: Lugol solution 5-10 gtt three times daily, or 2-6 gtt twice or three times daily given 10-21 days prior to surgery has been used. Use for longer than 14 days can lead to "iodide escape" with rebound thyrotoxicosis, and should be avoided. In pregnant women there is a risk of fetal goiter, although brief administration of lower doses (6-40 milligrams per day) can be considered. Potassium iodide (SSKI, PIMA) 1-2 gtt three times daily mixed in juice or water has also been given. Administration of these preparations should be under the direction of the operating surgeon.

Radiation emergencies: Potassium iodide (KI) should be taken just prior to, or as soon as possible after exposure. For adults exposed to 10 centigrays (cGy) of radiation or more, KI 130 milligrams is given (for pregnant or lactating women, 120 milligrams KI is administered for radiation exposure of 5cGy or more).

Skin/wound sterilization: Various concentrations of iodine have been used, for example 2% tincture or 2% aqueous solution to affected areas; 10% povidone-iodine applied prior to insertion of catheters; 0.9% iodine ointment for diabetic foot ulcers; and 1% povidone-iodine for wound irrigation. Use as directed.

Upper airway sterilization: 1% povidone-iodine solution inhaled via nebulizer twice daily has been used, with gargle twice daily.

Water sterilization: Salt iodization of water supplies on a large-scale basis can be performed with the addition of iodide or iodate salt with an iodine content varying from 7-100 milligrams per kilogram of salt. For individual use, tincture of iodine 3-10 drops per quart of water has been used, with 15 minutes for anti-microbial effects to occur.

Children (younger than 18 years):
Recommended Daily Allowance (RDA): 50 micrograms daily for infants 0-12 months; 90 micrograms daily for 1-8 years; 120 micrograms daily for 9-13 years; 150 micrograms daily for 14-18 years.

Adequate Intake (AI) for infants: 110 micrograms daily for ages 0-6 months; 130 micrograms daily for 7-12 months.

Tolerable Upper Intake Levels (UL): 200 micrograms per day for ages 1-3 years; 300 micrograms per day for 4-8 years; 600 micrograms per day for 9-13 years; 900 micrograms per day for 14-18 years (including pregnancy and lactation).

Iodine deficiency: Iodine deficiency is rare in industrialized countries due to supplementation of table salt and cattle feed with iodine. In areas of endemic iodine deficiency, various doses of iodine have been used as prevention or treatment in children, including 150 micrograms per day.

Ophthalmia neonatorum prevention: 1 drop of 2.5% povidone-iodine applied at birth has been used. No advantage of a second drop has been found.

Radiation emergencies: Potassium iodide (KI) should be taken just prior to, or as soon as possible after exposure. For infants, babies, and children, KI is administered for exposure of 5 centigrays (cGy) or more. For birth through one month, 16 milligrams can be administered; for one month through three years, 32 milligrams can be administered; for 3-12 years, 65 milligrams can be administered; for adolescents ages 12-18 years, 65 milligrams can be administered (or up to 120 milligrams if the adolescent is approaching adult size).
Skin/wound sterilization: Various concentrations of iodine have been used, for example 2% tincture or 2% aqueous solution to affected areas.

Thyroid disorders: Children should be managed under medical supervision.

Safety
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements.

There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies
Some individuals are allergic/hypersensitive to iodide or to organic preparations containing iodine. Hypersensitivity reactions may involve rash, angioedema (throat swelling), cutaneous/mucosal hemorrhage (bleeding), fever, arthralgias (joint pains), eosinophilia (abnormal blood counts), urticaria (hives), thrombotic thrombocytopenic purpura, or severe periarteritis (inflammation around blood vessels). Reactions can be severe and deaths have occurred with exposure. Iodine-based products should be avoided if there is known allergy/hypersensitivity to iodine.

Topical use of iodine preparations may irritate/burn tissues and cause sensitization in some individuals.

This review does not comprehensively cover the use of iodine-based intravenous contrast media for CT scan imaging, although serious life-threatening allergic reactions have been associated with use. Individuals with known or suspected iodine hypersensitivity should inform their physician prior to receiving contrast media.

Side Effects and Warnings
Note: This review does not cover adverse effects associated with intravenous iodine-based contrast agents used for CT scan imaging, or radioactive iodine.

Iodine preparations used orally (by mouth) or topically (on the skin) are generally considered to be safe in healthy non-allergic individuals when used in recommended amounts, not exceeding tolerated upper limits. Higher amounts taken acutely or chronically may result in adverse effects.

Acute iodine poisoning is rare and generally occurs only with doses of many grams. Symptoms may include burning of the mouth, throat, and stomach, fever, nausea, vomiting, diarrhea, cardiovascular compromise, and loss of consciousness/coma.

Chronic iodism, also known as iodide intoxication, may cause eye irritation, eyelid swelling, unpleasant/metallic taste, burning or swelling of the mouth/throat, soreness of the gums/teeth, increased salivation, gastrointestinal upset, diarrhea, anorexia, flu-like symptoms, sneezing, cough, pulmonary edema (fluid in the lungs), confusion, headache, fatigue, depression, numbness, tingling, pain, weakness, muscle aches, easy bruising, irregular heart beat, or acne-like skin lesions. Prolonged excess intake of iodides can lead to thyroid gland dysfunction including hypo- or hyperthyroidism, parotiditis, thyroid gland hyperplasia (enlargement), thyroid adenoma, goiter, autoimmunity, and elevated thyroid stimulating hormone (TSH) levels.
Prolonged excess intake of iodides can lead to thyroid gland dysfunction including hypo- or hyperthyroidism, thyroid gland hyperplasia (enlargement), thyroid adenoma, goiter, autoimmunity, and elevated thyroid stimulating hormone (TSH) levels. Individuals with autoimmune thyroid disease (AITD) may have increased sensitivity to adverse effects of iodine.

Those with previous iodine deficiency or nodular goiter may be particularly susceptible.

Topical cadexomer iodine has been associated with local burning sensation in clinical trials. Cutaneous (skin) intolerance may develop with the topical use of iodinated polyvidone. Other reported reactions to tinctures include rash, blistering, crusting, irritation, itching, or erythema (reddening) of skin. Topical use of iodine may stain the skin.

Sodium iodide should be used cautiously in those with gastrointestinal obstruction.

Povidone-iodine bladder irrigation has been associated with increased risk of urinary tract infection.

It has been suggested that application of povidone-iodine to wounds (particularly surgical wounds) may locally suppress immune cells and wound healing, and increase susceptibility to local infection.

Eyelid edema may result from administration of povidone-iodine.

Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in patients with pulmonary edema, bronchitis, or known tuberculosis.

Sodium iodide should be used cautiously in those with renal failure. Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in those with hyperkalemia. (Note: This review does not cover adverse effects associated with intravenous iodine-based contrast agents used for CT scan imaging. However, such contrast agents can cause impairment of kidney function including permanent damage. Individuals with a history of kidney disease or diabetes may be particularly susceptible. This concern should be discussed with the patient's physician prior to receiving intravenous contrast.)

Pregnancy and Breastfeeding
Pregnancy: Iodine requirements are increased during pregnancy. Iodine supplementation during pregnancy may be particularly relevant in areas of endemic iodine deficiency, such as non-industrialized nations. Iodine deficiency during pregnancy has been associated with an increased incidence of miscarriage, stillbirth, birth defects, and mental retardation. Moreover, severe iodine deficiency during pregnancy may result in congenital hypothyroidism in the newborn. In contrast, excess iodine intake by pregnant women may lead to effects of excess iodine in the fetus/newborn, including thyroid dysfunction or skin irritation.

Labor: It has been suggested to avoid topical use of povidone-iodine for perianal preparation during delivery or postpartum antisepsis due to possible iodine absorption by the newborn, or absorption by the mother leading to increased breastmilk iodine concentrations. Other reports suggest that this may not be a significant concern.

Breastfeeding: Iodine supplementation during breastfeeding may be particularly relevant in areas of endemic iodine deficiency, such as non-industrialized nations. Infants are particularly vulnerable to the effects of iodine deficiency, and iodine deficient women may not be able to provide sufficient iodine in their breastmilk.

Interactions
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs
Amiodarone (Cordarone®) contains significant amounts of iodine. Plasma iodine levels may be increased and additive with iodine supplements. Thyroid function should be monitored.
Concomitant use of angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) with potassium iodide increases the risk of hyperkalemia (high blood potassium levels). Examples of ACE inhibitors include benazepril (Lotensin®), captopril (Capoten®), enalapril (Vasotec®), fosinopril (Monopril®), lisinopril (Prinivil®, Zestril®), moexipril (Univasc®), perindopril (Aceon®), quinapril (Accupril®), ramipril (Altace®), and trandolapril (Mavik®). The ARBs include losartan (Cozaar®), valsartan (Diovan®), irbesartan (Avapro®), candesartan (Atacand®), telmisartan (Micardis®), and eprosartan (Teveten).
Additive hypothyroid effects may occur with the use of iodine products in combination with antithyroid drugs (methimazole, propylthiouracil).

Additive hypothyroid effects may occur with the use of iodine products such as potassium iodide in combination with lithium salts. Lugol solution can increases lithium toxicity by inducing additive hypothyroid effects.

Concomitant use of potassium iodide with potassium-sparing diuretics may increase the risk of hyperkalemia (high blood potassium levels). Examples of potassium-sparing diuretics include spironolactone (Aldactone®), Triamterene (Dyrenium®), and amiloride (Midamor®).

Interactions with Herbs and Dietary Supplements
Bugleweed ( Lycopus virginicus/Lycopus europaeus ) may reduce iodine uptake.

High iodine content can be found in kelp/seaweed/bladderwrack, and may add to the effects of iodine supplementation.

Ingestion of lithospermum may lower thyroid hormone blood levels, and may interact with the effects of iodine on thyroid hormone levels.

Selenium deficiency may exacerbate the effects of iodine deficiency.

Methodology
This information was edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Ethan Basch, MD (Memorial Sloan-Kettering Cancer Center); Elizabeth Camacho, PharmD (University of Rhode Island); Paul Hammerness, MD (Harvard Medical School); Catherine Meaghan McGrath, PharmD (University of Rhode Island); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Wendy Weissner, BA (Natural Standard Research Collaboration).

Selected references

Azizi F, Mirmiran P, Hedayati M, et al. Effect of 10 yr of the iodine supplementation on the hearing threshold of iodine deficient schoolchildren. J Endocrinol Invest. 2005 Jul-Aug;28(7):595-8.

Below H, Behrens-Baumann W, Bernhardt C, et al. Systemic iodine absorption after preoperative antisepsis using povidone-iodine in cataract surgery-- an open controlled study. Dermatology. 2006;212 Suppl 1:41-6.

Bibbo C, Patel DV, Gehrmann RM, et al. Chlorhexidine provides superior skin decontamination in foot and ankle surgery: a prospective randomized study. Clin Orthop Relat Res. 2005 Sep;438:204-8.

Chaudhary U, Nagpal RC, Malik AK, et al. Comparative evaluation of antimicrobial activity of polyvinylpyrrolidone (PVP)-iodine versus topical antibiotics in cataract surgery. J Indian Med Assoc 1998;96(7):202-204.

Hansmann F, Kramer A, Ohgke H, et al. [Lavasept as an alternative to PVP-iodine as a preoperative antiseptic in ophthalmic surgery. Randomized, controlled, prospective double-blind trial] Ophthalmologe. 2005 Nov;102(11):1043-6, 1048-50.

Harihara Y, Konishi T, Kobayashi H, et al. Effects of applying povidone-iodine just before skin closure. Dermatology. 2006;212 Suppl 1:53-7.

Hollowell JG, Staehling NW, Hannon WH, et al. Iodine nutrition in the United States. Trends and public health implications: iodine excretion data from National Health and Nutrition Examination Surveys I and III (1971-1974 and 1988-1994). J Clin Endocrinol Metab 1998;83(10):3401-3408.

Ibrahim AI, Rashid M. Comparison of local povidone-iodine antisepsis with parenteral antibacterial prophylaxis for prevention of infective complications of TURP: a prospective randomized controlled study. Eur Urol 2002;41(3):250-256.

Kahaly G, Dienes HP, Beyer J, et al. Randomized, double blind, placebo-controlled trial of low dose iodide in endemic goiter. J Clin Endocrinol Metab 1997;82(12):4049-4053.

Kalantar-Hormozi AJ, Davami B. No need for preoperative antiseptics in elective outpatient plastic surgical operations: a prospective study. Plast Reconstr Surg. 2005 Aug;116(2):529-31.

Liesenkotter KP, Gopel W, Bogner U, et al. Earliest prevention of endemic goiter by iodine supplementation during pregnancy. Eur J Endocrinol 1996;134(4):443-448.

Nishimura C. Comparison of the antimicrobial efficacy of povidone-iodine, povidone-iodine-ethanol and chlorhexidine gluconate-ethanol surgical scrubs. Dermatology. 2006;212 Suppl 1:21-5.

Papanastasiou L, Alevizaki M, Piperingos G, et al. The effect of iodine administration on the development of thyroid autoimmunity in patients with nontoxic goiter. Thyroid 2000;10(6):493-497.

Richter R, Below H, Kadow I, et al. Effect of topical 1.25% povidone-iodine eyedrops used for prophylaxis of ophthalmia neonatorum on renal iodine excretion and thyroid-stimulating hormone level. J Pediatr. 2006 Mar;148(3):401-3.

Zimmermann MB, Connolly K, Bozo M, et al. Iodine supplementation improves cognition in iodine-deficient schoolchildren in Albania: a randomized, controlled, double-blind study. Am J Clin Nutr. 2006 Jan;83(1):108-14.

November 01, 2006.


ZINC:

Zinc Helps Kids Grow
By Jennifer Warner, WebMD Medical News

May 24, 2002 -- Some infants and children may benefit from adding zinc to their diets. New data suggest that increasing the amount of this mineral may help children reach a healthy height and weight.

"Because of the important functional consequences of zinc deficiency for children's growth and other health outcomes, interventions to improve zinc ... [in the diet] should be considered in those populations at particularly high risk of zinc deficiency," write the authors of a report published in the June issue of the American Journal of Clinical Nutrition.

Zinc is a mineral found in a variety of foods such as red meat, whole-grain breads and cereals, dried beans, and seafood. It is also found in small amounts in breast milk.

Zinc is vital for the normal growth and development of the reproductive organs and brain and plays a role in the normal functioning of the immune system and many other processes in the body. Recently, zinc deficiency has been linked to decreased growth, increased colds and infections, impaired memory, learning disabilities, and poor attention span. The deficiency is a major problem in developing countries; for instance, 70% of school age children in Thailand are deficient in zinc.

In the U.S., zinc deficiency in children is not well recognized, although it affects an estimated 6% of girls and 10% of boys overall. Disadvantaged children are especially at risk -- more than 50% of poor children and 30% of non-poor children aged 1-5 get less than 70% of the Recom-mended Dietary Allowance of zinc (10 milligrams per day for children). In fact, recent data suggest that of 16 key nutrients, more children were deficient in zinc than in any other nutrient.

This new report looked at 33 studies on the effects of zinc supplementation on children up to 10 years old that were published between 1976 and 2001.

Overall, zinc supplementation produced very significant positive effects on both height and weight measures of the children. And the effect was even greater among children who already suffered from stunted growth or were underweight.

Researchers say it is hard to quantify the impact because the effects vary according to the age of the child, duration of supplementation, and other factors. But they cite the example of a Guatemalan study that found three years of zinc supplementation (from 3 to 36 months of age) was responsible for nearly an inch in additional growth.

Currently, scientists do not believe there is enough data to recommend widespread zinc supplementation in U.S. children as other studies of zinc's benefits have been inconclusive. In addition, scientists are unsure as to how much is enough; too much zinc can be as dangerous as a deficiency.

Adequate zinc can be obtained thorough a well-balanced diet of a variety of foods. Those foods include red meat, nuts, shellfish, potatoes with skins, beans, and mushrooms.

© 2002 WebMD Inc. All rights reserved.

Have a Cold? Think About Zinc
By Roxanne Nelson, WebMD Medical News, Reviewed By Merle Diamond, MD

Aug. 14, 2000 -- Sneezes, sniffles, that all over blah, achy feeling ... the average American gets between two and six colds a year, and so far, treatments have been ineffective at snuffing them out. But now researchers have found that zinc lozenges may actually cut the time spent suffering from a cold and lessen the symptoms.

In a study that appears in the current issue of the Annals of Internal Medicine, researchers from Wayne State University in Michigan found that patients who took zinc lozenges recovered almost twice as quickly as those who took a placebo. These findings fly in the face of at least five previous trials that didn't show a beneficial effect of zinc.

Led by Ananda Prasad, MD, PhD, a professor of medicine at Wayne State University, the researchers gave either zinc lozenges or a placebo to 48 individuals who had come down with cold symptoms within the previous 24 hours. Each person had to have at least two standard cold symptoms, such as sneezing, sore throat, fever, cough, and muscle aches.

The colds of patients taking the zinc lozenges lasted an average of four and a half days, while the colds of those taking the placebo had symptoms for eight days. Coughing stopped in the zinc group in half the time of the placebo group, and runny noses cleared up about two days sooner.

Prasad acknowledges in the study that previous research has not had such encouraging results. He points out to WebMD, however, that certain problems in previous studies may account for the differences in results. Some of the studies, he says, may have used a type of lozenge that doesn't release the zinc properly when a person takes it in his mouth.

"The dosage also has to be adequate," Prasad says. "I think one study used half the dose that we did, and the zinc must be taken within 24 hours of symptom onset."

Ronald Turner, MD, doesn't think this study will have much impact on usage by the public at large. "The data on zinc treatment have been extremely inconsistent from study to study," he says. "And zinc has been available to the public for some time. The product is available as a dietary supplement, and usage is probably unrelated to physician recommendation." Turner, who was not involved in the study, is a professor of pediatrics at the Medical University of South Carolina, and he has done unrelated research on zinc.

In an editorial that accompanied the study, Norman Desbiens, MD, with the University College of Medicine in Chattanooga, questions whether the study was properly "blinded," meaning, were the participants completely unaware of whether they were taking the placebo or the zinc. For the conclusions to be accurate, this is a very important issue in any study that uses a placebo to measure the effectiveness of a medication.

Turner agrees. "Inadequate blinding has been a consistent criticism of the zinc studies, and these authors do not appear to have adequately addressed the issue."

For example, the patients were asked to guess whether they were taking the placebo or the zinc. About half of those taking the zinc, and around a quarter taking the placebo, identified the lozenges correctly. But the researchers felt that these numbers were not high enough to negatively influence the results.

However, Desbiens feels the fact that more than three and a half times as many participants who received zinc correctly guessed that they were given zinc, may have affected the results of the study. "I suspect that the zinc and placebo had detectable differences, and therefore, a blind was not completely established," he writes.

Prasad writes that a test was done with healthy people who were given both types of lozenges, and it "showed that the zinc and placebo lozenges were indistinguishable in taste." He points out that none of the people involved in the study had ever previously used zinc lozenges, and in fact, they could not participate if they had used zinc in the past.

"This is the question I don't understand," Prasad tells WebMD, "how they would know if they've never had zinc or if they only taste one lozenge."

Everyone was only given one kind of lozenge -- either zinc or the placebo, he says, and they had no opportunity to taste the other kind. "It would be one thing if they had both kinds, but they didn't. So how would they be able to detect a difference in taste?"

The most common side effects from taking the zinc were a dry mouth and constipation. But since the amount of zinc that the study patients took is five times the current RDA of 15 mg, the researchers caution that zinc lozenges should not be taken for more than three days at a time. They recommend that if a person does not improve after three days of zinc treatment, then he should be evaluated for other type of respiratory illnesses or allergies.

Desbiens isn't convinced that taking zinc will help a cold, but the researchers disagree, saying their results show zinc can reduce the average duration and severity of the common cold.

"I think our results are very clear-cut," Prasad says. "The editorialist is saying that if they knew it was the zinc, it might have had an effect on their perception of whether or not they were getting better.

"But we measured symptoms," he adds. "It's hard to say you don't have symptoms if you're coughing or sneezing. Some of the people I recruited were physicians, and they're highly critical people and not easily convinced. So when they were cured in three days, they came to tell me and let me know."

The study was supported in part by an unrestricted grant from the George and Patsy Eby Research Foundation. George Eby holds patent rights to zinc lozenges and supplied both the zinc and placebo lozenges for this study. But Prasad writes the research funds were "unrestricted," and "the authors have neither industry connections nor personal financial conflicts of interest related to this study."  

© 2000 WebMD Inc. All rights reserved.



MANGANESE:

“Deficiency Diseases and Good Nutrition” (WaltonFeed.com)

Manganese activates many enzymes and vitamins in your body. It also helps to neutralize poisons in your blood. It helps in the production of such vital hormones as insulin. Manganese also works as an antioxidant to keep your cellular membranes healthy.

Vitamin C cannot work correctly without manganese. Enzymes are needed to direct vitamin C to detoxify the body, fight infection, build collagen, or perform one of its many other functions.

Manganese encourages the production of these enzymes, without which vitamin C could not function. In fact, a study done on animals given no manganese showed that when given hydralazine (poison), they died. When manganese was supplemented in the diet and the animals were administered hydralazine, they lived. It is believed to be due to the detoxifying effect of vitamin C, that can only be put to use when there is adequate manganese to activate it.

Manganese activates arginase, which also has a detoxifying function in the body. Ammonia is a substance naturally produced by your body. The only problem is 1/1000 of a milligram of the stuff in a quart of your blood will kill you! Arginase helps to bind ammonia and carbon dioxide to make urea, which is harmless. The urea is filtered out of your blood by the kidneys and excreted as urine.

The specialized beta cells in your pancreas need manganese to manufacture insulin. No manganese, no insulin. Insulin is what moves sugar from your bloodstream to your cells. If you don't get enough manganese, you could get a blood sugar disorder, like diabetes. An observation done on 122 diabetics and an identical control group showed diabetics to be twice as low in manganese than those without the disease.

Manganese activates choline, a phospholipid produced in the liver. Activated choline and ATP form acetyl choline. This compound functions as a neurotransmitter and works in the energy producing Krebs cycle. It also stimulates adrenaline and noradrenaline to be released from the adrenal glands. These hormones help you deal with stress.

Dopamine is a neurotransmitter and needs manganese to be produced. Sufferers of Parkinson's disease have a decreased ability to produce dopamine. Additional manganese may help decrease the effects of the disease.

Physiological Functions
Manganese is a cofactor for enzymes involved in hydrolysis, phosphorylation, decarboxylation, and transamination. It also promotes activities of transferases such as glycosyltransferase, and of glutamine synthetase and superoxide dismutase.

Deficiency
Manganese Deficiency in humans has not been documented, but has been induced experimentally in animals. Poor growth and abnormal reproduction have been observed in rats and mice.

Toxicity
No reported cases of manganese Toxicity resulting from dietary intake have been reported. Manganese Toxicity has been observed from inhalation manganese-containing dust by workers in mines and steel mills manifested by adverse effects on the central nervous system.


DEFICIENCY DISEASES AND GOOD NUTRITION

Manganese
Manganese activates many enzymes and vitamins in your body. It also helps to neutralize poisons in your blood. It helps in the production of such vital hormones as insulin. Manganese also works as an antioxidant to keep your cellular membranes healthy.

Vitamin C cannot work correctly without manganese. Enzymes are needed to direct vitamin C to detoxify the body, fight infection, build collagen, or perform one of its many other functions.

Manganese encourages the production of these enzymes, without which vitamin C could not function. In fact, a study done on animals given no manganese showed that when given hydralazine (poison), they died. When manganese was supplemented in the diet and the animals were administered hydralazine, they lived. It is believed to be due to the detoxifying effect of vitamin C, that can only be put to use when there is adequate manganese to activate it.

Manganese activates arginase, which also has a detoxifying function in the body. Ammonia is a substance naturally produced by your body. The only problem is 1/1000 of a milligram of the stuff in a quart of your blood will kill you! Arginase helps to bind ammonia and carbon dioxide to make urea, which is harmless. The urea is filtered out of your blood by the kidneys and excreted as urine.

The specialized beta cells in your pancreas need manganese to manufacture insulin. No manganese, no insulin. Insulin is what moves sugar from your bloodstream to your cells. If you don't get enough manganese, you could get a blood sugar disorder, like diabetes. An observation done on 122 diabetics and an identical control group showed diabetics to be twice as low in manganese than those without the disease.

Manganese activates choline, a phospholipid produced in the liver. Activated choline and ATP form acetyl choline. This compound functions as a neurotransmitter and works in the energy producing Krebs cycle. It also stimulates adrenaline and noradrenaline to be released from the adrenal glands. These hormones help you deal with stress.

Dopamine is a neurotransmitter and needs manganese to be produced. Sufferers of Parkinson's disease have a decreased ability to produce dopamine. Additional manganese may help decrease the effects of the disease.

Selenium:

From the National Institutes of Health:
Dietary Supplement Fact Sheet: Selenium
Office of Dietary Supplements • NIH Clinical Center • National Institutes of Health
What is selenium?

Selenium is a trace mineral that is essential to good health but required only in small amounts [1,2]. Selenium is incorporated into proteins to make selenoproteins, which are important antioxidant enzymes. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. Free radicals are natural by-products of oxygen metabolism that may contribute to the development of chronic diseases such as cancer and heart disease [2,3]. Other selenoproteins help regulate thyroid function and play a role in the immune system [4-7].
What foods provide selenium?

Plant foods are the major dietary sources of selenium in most countries throughout the world. The content of selenium in food depends on the selenium content of the soil where plants are grown or animals are raised. For example, researchers know that soils in the high plains of northern Nebraska and the Dakotas have very high levels of selenium. People living in those regions generally have the highest selenium intakes in the United States (U.S.) [8]. In the U.S., food distribution patterns across the country help prevent people living in low-selenium geographic areas from having low dietary selenium intakes. Soils in some parts of China and Russia have very low amounts of selenium. Selenium deficiency is often reported in those regions because most food in those areas is grown and eaten locally.

Selenium also can be found in some meats and seafood. Animals that eat grains or plants that were grown in selenium-rich soil have higher levels of selenium in their muscle. In the U.S., meats and bread are common sources of dietary selenium [9,10]. Some nuts are also sources of selenium.

Selenium content of foods can vary. For example, Brazil nuts may contain as much as 544 micrograms of selenium per ounce. They also may contain far less selenium. It is wise to eat Brazil nuts only occasionally because of their unusually high intake of selenium.
What is the recommended dietary intake for selenium?

Recommendations for selenium are provided in the Dietary Reference Intakes developed by the Institute of Medicine [12]. Dietary Reference Intakes (DRIs) is the general term for a set of reference values used for planning and assessing nutrient intake for healthy people. Three important types of reference values included in the DRIs are Recommended Dietary Allowances (RDA), Adequate Intakes (AI), and Tolerable Upper Intake Levels (UL). The RDA recommends the average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97-98%) healthy individuals in each age and gender group [12]. An AI is set when there is insufficient scientific data available to establish a RDA. AIs meet or exceed the amount needed to maintain a nutritional state of adequacy in nearly all members of a specific age and gender group. The UL, on the other hand, is the maximum daily intake unlikely to result in adverse health effects [12].

Results of the National Health and Nutrition Examination Survey (NHANES III-1988-94) indicated that diets of most Americans provide recommended amounts of selenium [13]. The INTERMAP study examined nutrient intakes of almost 5,000 middle-aged men and women in four countries in the late 1990s, including the U.S. The primary aim of the study was to evaluate the effect of dietary micronutrients on blood pressure. Each study participant completed four, 24-hour dietary recalls, during which they were asked to record everything consumed (food, beverages, and dietary supplements) over the previous 24 hours. Selenium intake was lowest among residents of China, the country with the highest known rate of selenium deficiency.

Mean dietary intake of selenium of U.S. participants was 153 μg for men and 109 μg for women. Both values exceed the recommended selenium intake for adults and are further evidence of adequate selenium intakes in the U.S. [14].

When can selenium deficiency occur?
Human selenium deficiency is rare in the U.S. but is seen in other countries, most notably China, where soil concentration of selenium is low [15]. There is evidence that selenium deficiency may contribute to development of a form of heart disease, hypothyroidism, and a weakened immune system [16,17]. There is also evidence that selenium deficiency does not usually cause illness by itself. Rather, it can make the body more susceptible to illnesses caused by other nutritional, biochemical or infectious stresses [18].

Three specific diseases have been associated with selenium deficiency:
Keshan Disease, which results in an enlarged heart and poor heart function, occurs in selenium deficient children.

Kashin-Beck Disease, which results in osteoarthropathy.

Myxedematous Endemic Cretinism, which results in mental retardation.

Keshan disease was first described in the early 1930s in China, and is still seen in large areas of the Chinese countryside with selenium poor soil [18]. Dietary intake in these areas is less than 19 micrograms per day for men and less than 13 micrograms per day for women, significantly lower than the current RDA for selenium [12]. Researchers believe that selenium deficient people infected with a specific virus are most likely to develop Keshan disease [18,19].

Selenium deficiency has also been seen in people who rely on total parenteral nutrition (TPN) as their sole source of nutrition [20,21]. TPN is a method of feeding nutrients through an intravenous (IV) line to people whose digestive systems do not function. Forms of nutrients that do not require digestion are dissolved in liquid and infused through the IV line. It is important for TPN solutions to provide selenium in order to prevent a deficiency [22]. Physicians can monitor the selenium status of individuals receiving TPN to make sure they are receiving adequate amounts.

Severe gastrointestinal disorders may decrease the absorption of selenium, resulting in selenium depletion or deficiency [23]. Gastrointestinal problems that impair selenium absorption usually affect absorption of other nutrients as well, and require routine monitoring of nutritional status so that appropriate medical and nutritional treatment can be provided.

Who may need supplemental selenium?
In the U.S., most cases of selenium depletion or deficiency are associated with severe gastrointestinal problems, such as Crohn's disease, or with surgical removal of part of the stomach. These and other gastrointestinal disorders can impair selenium absorption [24-26].

People with acute severe illness who develop inflammation and widespread infection often have decreased levels of selenium in their blood [27]. Physicians will evaluate individuals who have gastrointestinal disease or severe infection for depleted blood levels of selenium to determine the need for supplementation.

People with iodine deficiency may also benefit from selenium supplementation. Iodine deficiency is rare in the U.S., but is still common in developing countries where access to iodine is limited [28]. Researchers believe that selenium deficiency may worsen the effects of iodine deficiency on thyroid function, and that adequate selenium nutritional status may help protect against some of the neurological effects of iodine deficiency [6,7]. Researchers involved in the Supplementation en Vitamines et Mineraux AntioXydants (SU.VI.MAX) study in France, which was designed to assess the effect of vitamin and mineral supplements on chronic disease risk, evaluated the relationship between goiter and selenium in a subset of this research population. Their findings suggest that selenium supplements may be protective against goiter, which refers to enlargement of the thyroid gland [29].

As noted above, selenium supplementation during TPN administration is now routine [21,22]. While specific medical problems such as those described above indicate a need for selenium supplementation, evidence is lacking for recommending selenium supplements for healthy children and adults.

Selenium supplements
Selenium occurs in staple foods such as corn, wheat, and soybean as selenomethionine, the organic selenium analogue of the amino acid methionine [30,31]. Selenomethionine can be incorporated into body proteins in place of methionine, and serves as a vehicle for selenium storage in organs and tissues. Selenium supplements may also contain sodium selenite and sodium selenate, two inorganic forms of selenium. Selenomethionine is generally considered to be the best absorbed and utilized form of selenium.

Selenium is also available in 'high selenium yeasts', which may contain as much as 1,000 to 2,000 micrograms of selenium per gram [30]. Most of the selenium in these yeasts is in the form of selenomethionine. This form of selenium was used in the large scale cancer prevention trial in 1983, which demonstrated that taking a daily supplement containing 200 micrograms of selenium per day could lower the risk of developing prostate, lung, and colorectal cancer [32]. However, some yeasts may contain inorganic forms of selenium, which are not utilized as well as selenomethionine.

A study conducted in 1995 suggested that the organic forms of selenium increased blood selenium concentration to a greater extent than inorganic forms. However, it did not significantly improve the activity of the selenium-dependent enzyme, glutathione peroxidase [33].

Researchers are continuing to examine the effects of different chemical forms of selenium, but the organic form currently appears to be the best choice.


What are some current issues and controversies about selenium?

Selenium and cancer
Observational studies indicate that death from cancer, including lung, colorectal, and prostate cancers, is lower among people with higher blood levels or intake of selenium [34-40]. In addition, the incidence of nonmelanoma skin cancer is significantly higher in areas of the United States with low soil selenium content [37]. The effect of selenium supplementation on the recurrence of different types of skin cancers was studied in seven dermatology clinics in the U.S. from 1983 through the early 1990s. Taking a daily supplement containing 200 μg of selenium did not affect recurrence of skin cancer, but significantly reduced the occurrence and death from total cancers. The incidence of prostate cancer, colorectal cancer, and lung cancer was notably lower in the group given selenium supplements [41].

Research suggests that selenium affects cancer risk in two ways. As an anti-oxidant, selenium can help protect the body from damaging effects of free radicals. Selenium may also prevent or slow tumor growth. Certain breakdown products of selenium are believed to prevent tumor growth by enhancing immune cell activity and suppressing development of blood vessels to the tumor [42].

However, not all studies have shown a relationship between selenium status and cancer. In 1982, over 60,000 participants of the Nurse's Health Study with no history of cancer submitted toenail clippings for selenium analysis. Toenails are thought to reflect selenium status over the previous year. After three and a half years of data collection, researchers compared toenail selenium levels of nurses with and without cancer. Those nurses with higher levels of selenium in their toenails did not have a reduced risk of cancer [43].

Two important long-term studies, the SU.VI.MAX study in France and the Selenium and Vitamin E Cancer Prevention Trial (SELECT) study in the U.S., are now underway to further investigate the selenium/cancer prevention link.

The SU.VI.MAX Study is a prevention trial looking at the effects of antioxidant vitamins and minerals on chronic diseases such as cancer and cardiovascular disease. Doses of the nutrients provided in the study are one to three times higher than recommended intakes, including a daily supplement of 100 μg selenium. The SU.VI.MAX study, which began in 1994, has followed more than 12,000 adult men and women. This study was designed to continue for eight years, and the research community is eagerly awaiting the results of this study [44].

The SELECT study, a long-term study sponsored by the NIH, is investigating whether supplemental selenium and/or vitamin E can decrease the risk of prostate cancer in healthy men. Past evidence as well as pre-clinical trials for the SELECT study suggests that these two nutrients may be effective in preventing prostate cancer. A daily supplement containing 200 μg of selenium will be given to individuals in the selenium-only study group, while men in the combined-nutrients group will receive a daily supplement containing 200 μg selenium and 400 mg vitamin E. The study, which will span from 2001 to 2013, will include 32,400 healthy adult men [45].

Selenium and heart disease
Some population surveys have suggested an association between lower antioxidant intake and a greater incidence of heart disease [46]. Evidence also suggests that oxidative stress from free radicals, which are natural by-products of oxygen metabolism, may promote heart disease [47-49]. For example, it is the oxidized form of low-density lipoproteins (LDL, often called "bad" cholesterol) that promotes plaque build-up in coronary arteries [48]. Selenium is one of a group of antioxidants that may help limit the oxidation of LDL cholesterol and thereby help to prevent coronary artery disease [47-49]. Currently there is insufficient evidence available to recommend selenium supplements for the prevention of coronary heart disease; however, the SU.VI.MAX study mentioned earlier is looking at the effects of antioxidant nutrients such as selenium on heart disease.

Selenium and arthritis:
Surveys indicate that individuals with rheumatoid arthritis, a chronic disease that causes pain, stiffness, swelling, and loss of function in joints, have reduced selenium levels in their blood [50-51]. In addition, some individuals with arthritis have a low selenium intake [52].

The body's immune system naturally makes free radicals that can help destroy invading organisms and damaged tissue, but that can also harm healthy tissue [53]. Selenium, as an antioxidant, may help to relieve symptoms of arthritis by controlling levels of free radicals [54].

Current findings are considered preliminary, and further research is needed before selenium supplements can be recommended for individuals with arthritis.

Selenium and HIV
HIV/AIDS malabsorption can deplete levels of many nutrients, including selenium. Selenium deficiency is associated with decreased immune cell counts, increased disease progression, and high risk of death in the HIV/AIDS population [55,56]. HIV/AIDS gradually destroys the immune system, and oxidative stress may contribute to further damage of immune cells.

Antioxidant nutrients such as selenium help protect cells from oxidative stress, thus potentially slowing progression of the disease [57]. Selenium also may be needed for the replication of the HIV virus, which could further deplete levels of selenium [58].

An examination of 125 HIV-positive men and women linked selenium deficiency with a higher rate of death from HIV [59]. In a small study of 24 children with HIV who were observed for five years, those with low selenium levels died at a younger age, which may indicate faster disease progression [60]. Results of research studies have led experts to suggest that selenium status may be a significant predictor of survival for those infected with HIV [61].

Researchers continue to investigate the relationship between selenium and HIV/AIDS, including the effect of selenium levels on disease progression and mortality. There is insufficient evidence to routinely recommend selenium supplements for individuals with HIV/AIDS, but physicians may prescribe such supplements as part of an overall treatment plan. It is also important for HIV-positive individuals to consume recommended amounts of selenium in their diet.

What is the health risk of too much selenium?
High blood levels of selenium (greater than 100 μg/dL) can result in a condition called selenosis [62]. Symptoms of selenosis include gastrointestinal upsets, hair loss, white blotchy nails, garlic breath odor, fatigue, irritability, and mild nerve damage [2].

Selenium toxicity is rare in the U.S. The few reported cases have been associated with industrial accidents and a manufacturing error that led to an excessively high dose of selenium in a supplement [63,64]. The Institute of Medicine of the National Academy of Sciences has set a tolerable upper intake level (UL) for selenium at 400 micrograms per day for adults to prevent the risk of developing selenosis [12].

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