Selenium Health Benefits & Side Effects

Selenium is a trace mineral that can be found in nature. Selenium health benefits are prominent for humans. It is required for reproduction, thyroid gland function, infection prevention, DNA synthesis, and cell protection from oxidative stress generated by free radicals.

The highest concentration of selenium is found in Brazil nuts. Selenium is found in a variety of foods, including nuts, seeds, meat, and cereals. To ensure that newborns get enough selenium, infant formulae are supplemented with it.

The amount of selenium in food is determined by the soil in which it is grown. It was first thought to be a tellurium compound when it was discovered in 1817.

However, it eventually got medical attention due to its toxicity to industrial employees. Selenium has also been poisonous to animals that consume high-selenium plants. So an excess of this can be potentially harmful to health. 

Selenium Rich Foods
Selenium health benefits

Despite selenium’s beneficial effects on human health, consuming it in required amounts is essential. However, taking excess selenium may result in adverse health outcomes.

Science-Based Health Benefits of Selenium

1. Reducing Risk of Prostate Cancer is one of the Selenium health benefits

Prostate cancer can be caused by a variety of variables, including advanced age, obesity, and heredity. In addition, persons with prostate cancer may experience bladder control issues, erectile dysfunction, and other issues.

According to a study, optimal selenium levels in the body minimize the chance of males acquiring prostate cancer. Prostate cancer is prevented by selenium, which slows the growth and spread of cancer cells. Prostate cancer risk is inversely related to selenium levels in the blood and tissues.

Selenium has also been proven to lower the risk of various other cancers, including breast, colon, and lung cancers, in studies.

2. Selenium Contains Antioxidative Properties

Exposure to contaminants in the environment causes our bodies to produce free radicals. They are also produced by metabolic activities in the body. When these free radicals are produced in excess, they injure the tissues and organs. Antioxidants are critical for minimizing the harm produced by free radicals in the body. Selenium, for example, is a well-known antioxidant vitamin.

According to a research, selenium consumption may lower oxidative stress indicators. Furthermore, it boosts antioxidative activity, which reduces free radical damage.

3. Reduces Risk of Heart Disease

How Foods Rich In Selenium Affect Your Hair Health | Nutrafol
How Foods Rich In Selenium Affect You

Selenium health benefits also cover heart related diseases. Poor eating habits, heredity, lack of physical exercise, smoking, excessive cholesterol levels, and a variety of other factors have all been linked to heart disease. If left untreated, it can lead to major health problems like stroke and heart failure.

Selenium consumption has been linked to a lower risk of heart disease in studies. Selenium is a very powerful antioxidant. It works on the heart by shielding it from the effects of free radicals. Selenium also serves to reduce inflammation by decreasing oxidative lipid damage and artery blockage. As a result, selenium lowers the risk of heart attack and stroke.

4. Selenium Delays Onset of Alzheimer’s Disease

One of the selenium health benefits is for memory loss particularly Alzheimer’s disease. Alzheimer’s disease is caused by a combination of factors including lifestyle, environment, and heredity. As the illness progresses, it might make it harder to communicate, learn, or remember things.

Selenium in various stages has neuroprotective properties. According to a research, selenium’s antioxidant qualities can protect the brain from free radical damage. As a result, it slows the progression of Alzheimer’s disease.

Foods high in selenium, such as nuts, seeds, and seafood, are part of the Mediterranean diet, which is widely utilized to treat a variety of ailments. These meals can also help to lower your risk of Alzheimer’s disease.

5. Helps Treat Thyroid Disorders

Hypothyroidism, Grave’s disease, Hashimoto’s thyroiditis, and other conditions are caused by thyroid hormone fluctuations. Furthermore, if your thyroid gland is not functioning properly, it might impact your growth and development. Hair loss, weight loss, an irregular menstrual cycle, delayed growth, weariness, and other symptoms may occur.

 Food Sources Of Selenium
Food Sources Of Selenium

In its tissues, the thyroid gland has the highest concentration of selenium. Free radicals are produced by metabolic activities such as thyroid hormone release, as we all know. The thyroid gland is protected from oxidative damage by selenium. Thyroid diseases may benefit from selenium, according to a research.

6. Reduceing Inflammation in Selenium Health Benefits

Selenium improves the immune response. A study found that the selenoprotein formed from dietary selenium reduces the inflammatory response. These are associated with several diseases such as allergy, asthma, inflammatory bowel disease, etc. It acts by decreasing the over-activation of the immune system. It also strengthens the body’s immunity against infectious pathogens that cause influenza and tuberculosis.

7. Selenium Health Benefits; Aids in Weight Loss

Unhealthy weight growth can result in a variety of health problems, including obesity and heart disease. Selenium is important for metabolism because it modulates thyroid hormone activities and secretion.

According to one of the lastest research, getting enough selenium might help you maintain a healthy metabolic rate. As a result, getting enough selenium might help you lose weight. When consumed in excess of the recommended dose, however, selenium can have the opposite effect.

8. Prevents Premature Birth

Nutrients such as zinc, selenium, iron, folate are essential for the healthy growth and development of the baby during pregnancy. Studies have found that selenium is crucial for a baby’s healthy birth. Intake of appropriate amounts of selenium prevents adverse pregnancy outcomes such as premature birth and foetal growth restriction.

9. Selenium Health Benefits in Improve Fertility

Some research studies suggest that selenium intake improve fertility in women. In addition, selenium helps enhance reproductive function by keeping follicular fluid healthy. It is also beneficial in improving sperm count and motility in men.

Selenium Health Benefits affected by Deficiency

Selenium is essential for the proper functioning of the thyroid gland and many other systems in our body. Low levels of selenium may disrupt the normal processes and may lead to:

  • Fatigue
  • Hair loss
  • Brain fog
  • Weakened immunity
  • Weak muscles
  • Infertility 

The deficiency of selenium can lead to specific disease conditions. 

Keshan Disease

Keshan disease is a serious condition that can lead to cardiovascular disease, stroke, or death if left untreated. Keshan illness can be treated or managed, but it cannot be cured. Women and children are the most typically affected. According to studies, it can be caused by a lack of selenium. It is occasionally accompanied with microbial infection.

Keshan disease
Keshan disease


  • Nausea
  • Vomiting
  • Loss of appetite
  • Dizziness
  • Chills
  • Irregular heartbeat
  • Fatigue
  • Inflammation
  • Hair loss

In worst cases, it may lead to severe complications, such as:

  • Cough with blood
  • Severe shortness of breath
  • Congestive heart failure
  • Fainting
  • Palpitation
  • Stroke

Kashin Disease

Low selenium levels are linked to this joint and bone condition. Other variables, however, have a role in the development of this disease. It is quite frequent among children. According to studies, persons with this condition have less growth and have more bone deformities.


  • Pain and stiffness in joints
  • Inability to move joints
  • Enlarged joints

People of all age groups should take the recommended doses of selenium. It will help them with proper growth and development. However, it is essential to ensure that you do not consume in excess. Also, it is preferable to take selenium along with a meal rather than on an empty stomach. The recommended intake should be:

  • 0-6 Months: 15mcg
  • 7 months-3 years: 20mcg
  • 4-8 years: 30mcg
  • 9-13 years: 40mcg
  • 14 years and above: 55mcg
  • Pregnant women: 60mcg
  • Breastfeeding women: 70mcg

Food Sources For Selenium Health Benefits

1. Brazil Nuts

7 Proven Health Benefits of Brazil Nuts
Brazil Nuts

They’re high in antioxidants and minerals. The largest concentration of selenium is found in Brazil nuts, which also contain a good quantity of zinc. Furthermore, a research found that eating only one serving of Brazil nuts can significantly enhance the blood lipid profile of healthy participants.

This is due to the fact that they are nutrient-dense and aid in heart health. They also help other organs, such as the brain and kidneys, to work properly.

Nutritional Values

As per USDA, 100g of brazil nuts contain:

  • Energy: 659kcals
  • Carbohydrates: 11.7g
  • Protein:14.3g
  • Fat: 67.1g
  • Fibre:7.5g
  • Calcium: 160mg
  • Iron: 2.43mg
  • Zinc: 4.06mg
  • Selenium: 1920µg

2. Tuna

Tuna is an excellent source of high-quality protein. It is low in calories and fat and helps build muscle while reducing body fat. In addition, they are highly nutritious as they contain reasonable amounts of calcium, B complex vitamins, etc.

Nutritional Values

As per USDA, 100g of tuna contains:

  • Energy: 85kcals
  • Carbohydrates: 0.08g
  • Protein:19g
  • Fat: 0.6g
  • Calcium: 18mg
  • Iron: 1.67mg
  • Zinc: 0.66mg
  • Selenium: 67.8µg

3. Turkey

Turkey is another low-carb, high-protein meal. It’s loaded with B vitamins, zinc, and selenium. It’s a tasty and healthful side dish for almost any lunch entrée.

Nutritional Values

As per USDA, 100g of turkey contains:

  • Energy: 213kcals
  • Carbohydrates: 0g
  • Protein:27.1g
  • Fat: 10.4g
  • Calcium: 31mg
  • Iron: 1.56mg
  • Zinc: 3.77mg
  • Selenium: 28.4µg

4. Cottage Cheese

Curd cheese, such as cottage cheese, is a form of curd cheese. It’s tasty and nutritious, with low fat, high protein, selenium, calcium, and a variety of other minerals. You may use them in salads, eggs, toast, and a variety of other dishes.

Why Cottage Cheese Is Super Healthy and Nutritious
Nutritional Values

As per USDA, 100g of cottage cheese contains:

  • Energy: 82kcals
  • Carbohydrates: 4.31g
  • Protein: 11g
  • Fat: 2.3g
  • Calcium: 103mg
  • Iron: 0.13mg
  • Zinc: 0.61mg
  • Selenium: 14.6µg

5. Sunflower Seeds

Sunflower seeds aid in the regulation of the menstrual cycle, the prevention of heart disease, and the enhancement of immunity. They are, nevertheless, heavy in calories and should be used in moderation.

Nutritional Values

As per USDA, 100g of sunflower seeds contain: 

  • Energy: 657kcal
  • Carbohydrates: 17.1g
  • Protein: 21g
  • Fat: 56.1g
  • Calcium: 78mg
  • Iron: 5.2mg
  • Zinc: 6mg
  • Selenium: 80.4µg

Possible Side Effects & Precautions of Selenium

Taking selenium supplements according to a physician’s prescription is advisable. However, it is essential to be cautious. Intake should not cross the safe upper limits. These upper limits are:

  • 0-6 months: 45mcg
  • 7-12 months: 46mcg
  • 1-3 years: 90mcg
  • 4-8 years: 150mcg
  • 9-13 years: 280mcg
  • 14 years and above: 400mcg

Thyroid Disorders

Selenium supplementation may aggravate hypothyroidism. It is more common in those who are iodine deficient. Iodine and selenium should be taken simultaneously in this scenario. Consult your doctor for the best dose and treatment options.

Sperm Motility

Though studies show that selenium enhances fertility, it’s important to remember that too much selenium might have the opposite effect. Because selenium reduces the ability of sperm to move, it reduces fertility. As a result, only take selenium up to the tolerated maximum limits.

Selenium can Cause Kidney Disease

Excessive intake of selenium can be potentially harmful to the kidney. Therefore, it is essential to consume selenium within safe limits in patients with kidney failure or people undergoing dialysis. Studies have found that excessive selenium intake may result in acute renal failure.


Case studies have found that high levels of selenium intake may lead to congenital disabilities in babies. It may also lead to complications in the pregnancy. Hence, it is essential to consume selenium within tolerable limits.

Other Medications

Selenium supplements interfere with a few medications when taken together. One such medication is warfarin. Studies show that selenium may alter the activity of warfarin. Therefore, it would help if you discussed with your physician before consumption.


Studies show that selenosis occurs due to a high selenium intake. For example, it can be due to increased consumption of selenium-rich foods such as brazil nuts. It may also occur due to foods grown in soil with high selenium content or excessive selenium supplementation.


  • Nausea
  • Vomiting
  • Discolouration of nail
  • Brittle nails
  • Hair loss
  • Fatigue
  • Irritability
  • Foul odour or ‘garlic breath.’

Selenium is essential for our bodies’ day-to-day operations. Excess selenium intake, on the other hand, might have negative consequences. Both selenium deficiency and toxicity can have negative health consequences. As a result, it’s critical to exercise caution when taking a selenium supplement.

Always see a physician before using a supplement to discuss the advantages and possible effects. It’s also critical to avoid any medicines that may interfere with selenium supplements.

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