Selenium Vegetarian

What is Selenium?

Selenium is an essential mineral with many important functions in the body. It’s considered a trace mineral because humans don’t need a huge amount to stay healthy.

What Does Selenium Do in the Body?

There are many important roles selenium plays in the body including:

• Oxidant defense: Selenium protects the body’s cells from damage by free radical compounds ^1, 2.
• Reproduction: Adequate selenium intake is needed for proper reproductive function/ growth of a baby ³.
• Thyroid function: Selenium is required for its antioxidant function within the thyroid and for thyroid hormone metabolism ⁴.
• DNA synthesis: Selenium may help prevent and repair DNA damage ⁵.

Selenium gets incorporated into proteins that primarily function as antioxidants. Antioxidants keep cells in the body healthy and free from damage. Selenium is also thought to have anti-inflammatory effects and support proper immune function including antiviral protection ⁶.

Since selenium is an essential mineral, adequate amounts must be consumed through diet (or supplements if needed). Always speak to your doctor before starting new supplements; excessive intake of selenium is known to be harmful .

Selenium is unevenly distributed in the earth’s soil as a result of ancient volcanic eruptions. Because of this, intake varies widely around the world, which makes it difficult to produce accurate food tables that show how much selenium different foods contain.

In parts of Europe, selenium levels in the soil can be low so farmed animals are often fed supplements so that their meat and milk will contain it – in the same way that vitamin B12 supplements are given to animals.

However, surveys indicate that the average UK adult’s intake is 48 micrograms a day, lower than the recommended amount. So meat and milk are obviously not providing enough as most people still consume these.

If you’re concerned, you could cut out the middleman, avoid meat and dairy and take your own supplement, or just include more nuts and wholegrains in your diet. The NHS says that if you eat nuts, you should be able to get all the selenium you need from your daily diet.

Food (100g) Selenium (micrograms)

RNI: 60 micrograms for women and 75 micrograms for men

Brazil nuts 254
Sunflower seeds 49*
Green or brown lentils, dried, boiled 40
Cashew nuts, roasted and salted 34
Pecan nuts 12
Mushrooms, fried in corn oil 12
Wholemeal bread, toasted 11
Wholemeal spaghetti, boiled 6*
Red kidney beans, canned 6
Mung beans, boiled 5
Brown rice, boiled 4
Soya milk 4

The selenium content of selected foods

Source: Food Standards Agency, 2002. *Estimated value

Brazil nuts

Although selenium can be found in meat, fish and eggs, these foods also contain undesirable substances, including saturated animal fat and hormones while fish tend to be contaminated with toxic pollutants.

The richest plant sources of selenium are cereals, grains and Brazil nuts, which can contain very high amounts of 68-91 micrograms per nut, according to the US National Institutes of Health, and too many of those could cause you to go over the upper limit. Fruit and vegetables also provide small amounts of selenium.

Researchers from the University of Otago in New Zealand found that consuming just two Brazil nuts a day for 12 weeks increased the amount of selenium in the blood by over 60 per cent. They said that including Brazil nuts in the diet could avoid the need for supplements.

Nuts

Nuts are a healthy, nutritious food that provide an excellent source of vitamin E and magnesium. People who eat nuts have higher intakes of folate, beta-carotene, vitamin K, calcium, phosphorus, copper, selenium, potassium and zinc.

Nuts provide valuable phytochemicals and their antioxidant power is similar to that of broccoli and tomatoes. Eating a generous handful of mixed nuts a day – about 42 grams can reduce the risk of heart disease.

But how much selenium you eat is just part of the story; older age, alcohol and smoking are all associated with lower levels, suggesting that these factors may affect how well you absorb and store selenium. One study found that coffee, dairy products, eggs and white rice were all linked to lower levels while bread was linked to higher levels. It seems a wholegrain diet offers the most benefit – again!

Too much

Hair, skin and nail supplements commonly contain selenium in levels as high as 100 micrograms and more. However, too much selenium can lead to a condition called selenosis, which can result in nausea, fatigue, garlic breathe and the loss of hair, skin and nails!

In extreme cases, it can result in cirrhosis of the liver, pulmonary oedema and death. Recent evidence suggests too much selenium may also increase cholesterol levels. The NHS says that taking 350 micrograms or less a day of selenium supplements is unlikely to cause any harm.

However, one study found that 200 micrograms a day of selenium supplements increased the risk of aggressive prostate cancer among men with high selenium levels. So concerned were the researchers that they stopped the trial three years early.

They suggest that men over 55 should avoid taking selenium (and vitamin E) supplements at doses that exceed the recommended dietary intake. Another study found that people taking 200 micrograms of selenium a day had a higher risk of non-melanoma skin cancer. These negative effects of supplements appear greatest in those who already have high selenium levels in their blood.

Wholegrains, fruit, and vegetables

The belief that selenium can fight cancer and other diseases has boosted demand for supplements despite a lack of definitive evidence. For selenium, there’s a fairly narrow range between sufficient intake and toxicity.

The recommended amount is 60-75 micrograms a day and the UK’s Expert Group on Vitamins and Minerals set a safe upper limit for selenium at 450 micrograms a day. A quick search on the internet reveals that many supplements contain 100-200 micrograms of selenium; you can see how easy it would be to take too much.

The best way to get your full range of vitamins and minerals is to eat a healthy, balanced diet with a wide variety of wholegrains, fruit and vegetables. If you are going to take supplements, stick to the recommended intake.

Daily Intake Requirements of Selenium

The recommended daily intake of selenium for men and women over 18 years of age is 55 ug/day ⁷. This amount holds true for vegans or vegetarians.

Selenium absorption should be similar between plant-based and animal-based foods. The main concern for vegan selenium intake is the variation in selenium content of plant-based foods grown in different soil regions.

Selenium Deficiency

Selenium intake is somewhat dependent on geographical location because selenium is present in soil to varying levels depending on location ^2, 6. Certain areas of the world have soil that’s low in selenium. If the selenium content of soil is low, it can put the people in that area at higher risk of selenium deficiency ^2, 6.

Global food chains help to overcome this, but for consumers who tend to only purchase local produce, selenium levels are more of a concern.

Selenium deficiency is associated with many signs and symptoms including ^1, 6:

• Male infertility
• Fatigue
• Muscle weakness
• Hair loss
• Weakened immune system
• Exacerbation of iodine deficiency (and the signs and symptoms associated with low intake of iodine)

Selenium deficiency is also associated with certain diseases ¹:

• Keshan disease: Selenium deficiency, along with another stressor to the body (ex. a viral infection) can lead to Keshan disease. Keshan disease is a type of cardiomyopathy (a disease of the heart muscle).
• Kashin-Beck disease: A type of osteoarthritis associated with low selenium intake.

If you have any of the signs and symptoms listed above, seek a doctor immediately. These can also be indicative of other problems that require medical attention.

Selenium Toxicity

Preventing nutrient deficiency is often a primary concern when it comes to nutrition. However, when excessive quantities of certain nutrients are consumed (from food and/or supplements), they could produce toxic effects in the body. Selenium toxicity is rare, but it’s possible even from food sources alone. Selenium toxicity is called selenosis ¹.

Selenium toxicity signs and symptoms include ¹:

Many of these could be indicative of another condition and not necessarily selenium deficiency. Seek a doctor’s care if you ever experience signs or symptoms that are abnormal or concerning to you.

How to Consume Enough Selenium as a Vegan

Since selenium is present in soil, most plant-based foods grown in soil contain at least a small amount of selenium. Some foods like Brazil nuts, whole grains and legumes contain higher levels of selenium.

If you live in an area with adequate selenium in the soil and consume a variety of these foods, it’s likely that your selenium intake meets the requirements.

As shown in the chart below, selenium content varies widely in Canadian foods. Grain products tend to provide the highest levels of selenium but other foods like soy beans and tofu, along with certain nuts, seeds and different legumes also provide selenium.

Consuming a variety of foods and including whole grains should help you to meet selenium requirements.

Vegan Food Sources of Selenium

Here is a list of foods and their selenium content. Please note this data was pulled from the Canadian Nutrient File and is reflective of the average selenium content of foods analysed in Canada ⁸.

Local content of selenium may vary ⁸. Look for local food analyses as these will vary by region. Many government bodies publish food databases with nutrient content of the national food supply.

Selenium Supplements for Vegans

A common question and concern is if vegans require selenium supplements. Data seems to support that vegetarians and vegans in the US and Canada have adequate selenium status ². Therefore, it’s not routinely recommended for vegans to consume a selenium supplement.

If you live in an area with known low selenium soil concentration, you may want to speak to a doctor about testing your selenium levels. From this, your doctor may recommend a selenium supplement if it’s right for you.

It’s often best to meet nutrient needs from foods first before resorting to supplements. If you’re concerned about meeting your nutrient needs as a vegetarian or vegan, speak with a Registered Dietitian who specializes in plant-based nutrition!

Summary: Selenium for Vegans

Vegan selenium intake may be a concern, especially for those living in areas with low amounts of selenium in the soil. While selenium deficiency is rare, it is possible. On the other hand, selenium toxicity is also possible from high intake of selenium-rich foods like Brazil nuts, or from intake of supplements that contain high levels of selenium.

If you experience signs and symptoms of selenium deficiency or toxicity, please consult a doctor immediately.

It’s not typically recommended for vegans to routinely take a selenium supplement. Speak with your doctor or dietitian before starting any supplements and if you have any questions.