Does an Intake of Selenium Result in Weight Gain?

can selenium cause weight gain

What is Selenium?  

Selenium is one of the many trace elements that we need in our daily diets in order to maintain normal bodily function. Selenium aids in the proper working of the immune system, the up-keep of cognitive function and also helps with fertility in both sexes.

Selenium is an antioxidant mineral that boasts multiple health benefits. Found in both animal and plant-based sources, selenium can only be obtained through the diet or supplementation.

Can Selenium cause Weight Gain?  

Similarly to other minerals can we consume, selenium is absorbed by the body through the food we eat. Once absorbed it can interact with other chemical compounds in our body. This is where the health benefits of selenium unfold.  

Trace minerals and vitamins are both consumed in the same way and are essential to our overall health, but they are certainly different from one and other.

Vitamins are segregated into two groups, water-soluble and fat-soluble.

Water-soluble vitamins are sourced from foods such as fruit vegetables and grains, usually fibrous foods made up of mostly carbohydrates, starches, sugars, etc. Water-soluble vitamins are not stored by the body, so they need to be consumed often and in plentiful quantities. If you consume too many water-soluble vitamins, the body excretes them through urine and sweat.  

Fat-soluble vitamins come mainly from animal-based products such as meat, fish, eggs and dairy. As the name suggests, these vitamins are soluble in fat, so the body can actually store them, and use them as and when needed. Because the body holds on to these vitamins, they can build up over time, leading to negative symptoms and side effects.  

Is selenium fat soluble?

Unlike vitamins, trace minerals are not divided into these two categories, they can, however, be absorbed in different ways. Calcium is ingested and quickly absorbed into the blood much like a water-soluble vitamin. Selenium, on the other hand, is absorbed through a carrier protein and is stored by the body, much like a fat-soluble vitamin.  

What is the Impact of Selenium on my Weight?  

It is crucial that we get just the right amount of selenium in our diets. Consume too little and the functionality of the thyroid gland is compromised, consume too much and you run the risk of selenium toxicity.  

The thyroid gland produces all of the important hormones that regulate the bodies automated functions, including digestion, metabolism and heart rate. Keeping the thyroid in good health is imperative to overall well being and maintaining a healthy weight.  

Because of the seleniums effect on the thyroid, and in turn metabolism, there is a direct correlation between selenium and weight gain/loss.  

Too little selenium in the diet and the thyroid cannot function properly, resulting in a compromise in metabolic rate. A slower metabolic rate will usually lead to weight gain.  

Get too much selenium in the diet and you run the risk of toxicity. Selenium toxicity is rare and such high levels are not easy to obtain from a regular diet. It is, however, more possible when supplementing with capsules.  

Getting just the right amount of selenium in the diet will allow you to benefit greatly from the health benefits, including a boosted metabolism (thanks to a healthy thyroid) which can potentially lead to weight loss.  

Health Benefits of Selenium.  

Powerful antioxidant.  

Antioxidants are chemical compounds that reduce the number of free radicals in the body. Free radicals are a natural byproduct of normal bodily functions and play an important roll in protecting the body from sickness, viruses and disease.

Too many free radicals, however, can lead to cell damage. The consumption of drugs, smoking, alcohol can lead to an increase of free radicals, leading to oxidative stress. Oxidative stress damages healthy cells that can lead to a number of chronic health conditions.  

Selenium is a powerful antioxidant that reduces the number of free radicals in the body and the effects of oxidative stress.

Improved cardiovascular system.  

cardiovascular system

The proteins that make up selenium, called selenoproteins reduces the oxidative transformation of fats in the body. A reduction in this process prevents inflammation and the build-up of platelets in our arteries. The build-up of platelets can lead to a host of cardiovascular problems, such as high blood pressure, heart disease, heart attacks and stroke.  

Maintaining healthy levels of selenium in the body is a great way of reducing the effects of oxidative stress on the cardiovascular system.  

Reduced cognitive decline.  

Unfortunately, as we get older most of us will experience some form of cognitive or mental decline. The antioxidant properties of selenium can help to counteract this and slow down the mental sights of ageing.

Alzheimer's disease is the 6th leading cause of death in the US, responsible for approximately 83,000 fatalities per year. This number has lead to many studies searching for ways to reduce the effects of Alzheimer's and slow down its rate of progression.  

Studies Have shown that oxidative stress increases the onset and progression of Alzheimer’s, alongside other neurological diseases such as Parkinson’s and Multiple sclerosis. Selenium is an antioxidant, which minimises oxidative stress is there for believed to reduce this onset and progression. Some studies have shown that increasing levels of selenium in Alzheimer’s patients improve memory function, verbal skills and other mental functions.  

Increased thyroid functionality.  

Selenium and thyroid function are directly linked through the mineral's ability to protect the gland and allow it to function at its peak. Having enough selenium is essential for the thyroid gland to produce important thyroid hormones which are responsible for metabolism, growth and development.

Having just the right amount of selenium will not only combat the risk of thyroid disease, but also reduce the risk of: 

  • Graves decease 
  • Thyroid cancer
  • Hyperthyroidism
  • Subclinical hypothyroidism
  • Goitre
  • Autoimmune Hashimoto's thyroiditis  

Cancer prevention.  

Some studies have shown positive results that support the theory that selenium reduces the risk of certain cancers. As well as reducing oxidative stress and DNA damage, selenium increases the efficiency of the immune system.

A collective review of many studies found that those with higher levels of selenium in the blood had a lower risk of multiple cancers, including breast, lung and prostate.  

Reducing asthma.  

selenium deficiency symptoms

Asthma is a chronic respiratory disease that causes the airways of sufferers to inflame and narrow. Common symptoms include difficulty breathing, wheezing, general chest tightness and shortness of breath. Seleniums anti-inflammatory properties can reduce these symptoms and improve lung function. Increasing the daily intake of selenium through diet or supplementation has been shown to reduce the frequency of heightened asthma symptoms.  

Selenium Deficiency.  

How much selenium do you need?  

Most of us don’t give too much thought to our intake of selenium. Luckily, in most parts of the world deficiencies are rare as soils are rich with the trace element resulting in adequate intake through normal diet alone.

In some regions such as northern China, agricultural land is low in selenium which has led to a large proportion of the population developing selenium deficiency related symptoms.

It is suggested that both men and woman require 55 mcg of selenium per day. Although this number is increased when pregnant or breastfeeding and also adjusted if suffering from a decease that can lead to selenium deficiency, such as Crohn’s and IBS.  

Selenium deficiency symptoms.  

Over time the body starts to suffer when adequate amounts of selenium are not reached daily. The free radicals that selenium controls start to increase in number, more damage is dealt to healthy cells and the result is a decline of normal bodily function and general well-being.  

Hair loss.  

is selenium good for your thyroid

Selenium deficiency hair loss is a secondary symptom of hyperthyroidism. Selenium helps to transform thyroid T4 hormone into thyroid T3 hormone. This conversion is essentially an activation process that allows the hormone to work. If this conversion isn’t taking place at the required rate, there is a risk of developing hyperthyroidism related symptoms, one of which being hair loss.

Excessive fatigue.  

When suffering from fatigue, other dietary or lifestyle issues are usually the culprit. However, fatigue is also a prominent symptom of hyperthyroidism, so if your symptoms are consistent with others linked to hyperthyroidism, it may be the result of a selenium deficiency.  

Gaining weight.  

Again a lack of selenium is going to leave your thyroid unable to function as it should. Because of the thyroid's role to play in the regulation of metabolic rate, a problematic thyroid will usually result in the slowing down in metabolism. Having a slow metabolism means that the body can not metabolise, or convert the calories we consume into energy. Instead, our bodies will store those calories as fat.  

Healthy levels of selenium are needed in order to keep the thyroid functioning optionally and is a key element of maintaining a healthy weight.  

Getting sick regularly.

If you’re getting sick more regularly than usual you may have a compromised immune system. Selenium is the bundling block of the formation of selenoproteins, which is the bodies way of turning bad toxins into harmless byproducts. Without this process taking place, antibodies can not work at their best resulting in a weakened immune system. Having a poor immune system will make you more susceptible to illness.

Body feels under stress.  

Because oxidative stress damages healthy cells throughout the body, it can leave you feeling physically worn out and mentally stressed. No amount of rest and sleep is going to bring you right if the issue is not lifestyle by cellular. Selenium being a powerful antioxidant protects healthy cells and fights body stress at the source.  

Shortness of breath.  

One of the health benefits previously discussed was seleniums ability to improve the cardiovascular system.

Having too little Selenium in the diet has the opposite effect and the cardiovascular system suffers, leaving you with the feeling of lack of oxygen and shortness of breath. Because selenoproteins reduce inflammation in the body, not consuming enough selenium to make selenoproteins may leave you in the opposite state, inflamed. An Inflamed cardiovascular system can lead to high blood pressure, heart attacks, and stroke. There is also the potential for asthma sufferers symptoms to worsen.  

What food sources Contain Selenium?  

Selenium is a naturally occurring mineral found in many of our foods and drink. Selenium percentage in certain foods vary greatly as it is determined by the concentration of selenium in the soil. For example, a carrot grown in soil when there are low levels of selenium will in-turn contain low levels of selenium. A cow that grazes on feed grown in soil rich in selenium will produce beef that is high in selenium.

Some foods, regardless of where they are grown hold onto higher percentages of selenium, With the best sources coming from fish and nuts.  

Top 10 Sources of Selenium.

  1. Oysters are a fantastic source of selenium. A single offering of this tasty shellfish contains approximately 55% of your daily recommended amount. Oysters also contain other trace minerals in high concentration and are also a fantastic source of lean protein.  

how much selenium should i take daily for thyroid

  1. Mushrooms being widely available are an accessible source of selenium that you can easily find. Some mushrooms contain up to 10% of your daily amount in 1 cup. Shiitake mushrooms are thought to have the highest concentration.  
  2. Eggs A breakfast staple for most is surprisingly one of the best sources of selenium. 2 large eggs contain around 55% of your DV. Eggs are also a great protein source and contain lots of healthy cholesterol.  
  3. Halibut is a mild white-fleshed fish that is high in omega 3 and selenium. A single 6 ounce serving offers around 170% of the recommended DV.  
  4. Yellow fin tuna similarly to halibut contains around 170% of your DV per serving. Tuna, however, is considered an oily fish and as such contains even more healthy fats like omega 3 essential for overall health.
  5. Sunflower seeds are full of vitamins and minerals, including selenium. 1 ounce, around a handful, contains 27% of you DV. Sunflower seeds are also a great source of dietary fibre and plant-based protein.
  6. Chicken and other poultry are lean sources of protein and contain up to 12% of selenium DV per portion.  
  7. Sardines small is size, but big in the selenium department. Consuming only 4 of these little fish can see and intake of 46% of the DV. Sardines are also one of the best sources of vitamin B12 which helps keep the bodies nerve and blood cells healthy.
  8. Grains Whole grains such as brown rice are high in selenium, dietary fibre and complex carbohydrates. 1 cup of cooked brown rice contains 19 mcg of selenium (around 30% of your recommended daily amount.)  
  9. Brazil nuts are thought to contain the highest concentration of selenium of any food, with only 5 grams containing around 175% of the daily recommend amount. Because of these incredibly high levels, it is advised to moderate brazil nut consumption if your diet is already high in selenium, or else you run the risk of reaching toxicity.  

selenium deficiency hair loss

Dangers of Consuming too much Selenium.  

Although very much necessary for maintaining overall health, too much of anything can be harmful. Whilst selenium toxicity is rare and hard to do from diet alone, it is possible and a real risk that can leave you in a toxic state and can even be fatal in extreme cases.  

55 mcg is the recommended daily amount, but the body can tolerate up to 400mcg per day without seeing adverse effects. Consuming more than the daily DV doesn’t necessarily mean that you will see additional health benefits.

Signs of Selenium Toxicity.  

  • Tender or sore muscles
  • Muscle twitches and body tremors
  • Nausea/vomiting 
  • Feeling light-headed and dizzy 
  • Flushed cheeks and feeling clammy  

Severe toxicity can result in heart attack and kidney failure.  

How does selenium affect weight?  

The relationship between selenium and body weight is mostly thanks to the impact selenium has on your thyroid gland, and its ability to help it to produce certain hormones. These hormones that the thyroid produce helps to regulate multiple bodily functions, one of which being your metabolism.

Metabolic rate or metabolism is the speed of which your body can convert calories consumed into energy. Excess calories that don’t get converted are subsequently stored as fat. It is important that enough selenium is consumed to promote proper thyroid function and ensure optimal metabolic rate is reached. Selenium, thyroid, weight loss, all three are closely related.  

A recent selenium weight loss study showed that those with lower levels of selenium in their blood were at a higher risk of developing thyroid-related diseases which in turn would lead to a compromised metabolic rate.  

Is Selenium Good for your Thyroid?  

Selenium is not only good for your thyroid, it is essential to maintain its functionality and your general health. To prevent developing thyroid-related diseases you should aim to consume the daily recommended amount of 55 mcg. Consuming less than this can eventually lead to a deficiency that will reduce the efficiency and abilities of the thyroid gland.

If I am already suffering from thyroid-related complications, how much selenium should I take daily for thyroid recovery?  

Some practitioners suggest that when recovering from thyroid-related diseases, increasing daily selenium intake through supplementation can improve the rate of which the thyroid gland recovers and improves symptoms whilst doing so. Taking 200 mcg selenium capsules is the recommended daily dosage.

It is advised that anybody who looks to increase selenium through supplementation should first consult a qualified physician.  


Can selenium cause weight gain? In a word, no. The answer to that question is actually quite the opposite. Getting the recommended amount of selenium in your diet will aid in the proper function of your thyroid, which in turn, can improve metabolic rate.

Multiple studies have shown that getting an adequate intake of selenium can help to maintain health and reduce that chance of developing cardiovascular, respiratory, and mental problems such as heart disease, asthma and Alzheimer’s.  

Having a selenium deficiency can be detrimental to quality of life as general health and well-being goes into rapid decline. Complications of selenium deficiency such as hair loss, fatigue and weight gain can be easily avoided by maintaining healthy levels through a healthy balanced diet, and if required supplementation.  

On the other hand, as with anything, too much can have as many adverse effects as too little. Too much selenium can lead to selenium toxicity that comes along with a host of negative symptoms and can even lead to death. As a result of this risk, supplementation without proper consultation should be completely avoided. If you already have normal levels of selenium in your blood work, certain foods such as Brazil nuts and some fish should be eaten in moderation.