How to Boost Your Immune System

During this coronavirus pandemic it is especially important that we keep our immunity high. There are many foods, nutrients, and supplements that are known to boost our immune system. In this article we will go over the most popular immune boosters and how to take them, but first, let’s say a few words about the function and importance of the immune system.

The Immune System and its Role

The immune system is a powerful defense mechanism that your body uses to fight off viruses, bacteria, parasites, and fungi that can endanger your health. It is not a single organ, but rather a complex network of cells and tissues. When the immune system is working properly it can detect harmful organisms like bacteria or viruses and release specially designed cells, called white blood cells, to attack them.

The white blood cells are not the only parts of the body that protect you from harm. There are also physical barriers like your skin or the lining of internal organs that protect your body from the outside world. However, these protective barriers can be physically penetrated as a result of injuries, such as cuts or burns, which can open a path for germs to enter your body.

Sweat, tears, and mucus found in the digestive system, nasal passages, and eyes also fight the germs by flushing them out, and sometimes, killing them with their enzymes.

The lymph system, which is made up of a network of vessels, tissues, and fluid also has a role in the immune system. It collects dead cells and germs and filters them in the lymph-nodes before returning to your bloodstream. This is the reason why the lymph-nodes often swell as a result of infections.

The immune system operates by recognizing special markers called antigens, which work to identify friendly cells versus intruder cells. These intruder cells are not necessarily germs, they can also be foods, food components like gluten, or environmental factors like pollen. When the immune system recognizes a cell as a foreign cell and attacks it you can experience an allergic reaction.

Under attack, the immune system can create and use different kinds of cells to eliminate the intruder. These cells include:

·       Memory cells (T Cells and B cells)

·       Lymphocytes (white blood cells)

·       Mast cells

·       Basophils

·       Natural killer cells

·       Phagocytes

·       Antibodies

Newborns have an immune system that protects them from certain familiar threats. This is known as the innate immune system. As we grow, our immune system acquires new abilities that are necessary to provide additional protection from various threats.

This means that the immune system can learn to recognize new diseases and develop the best response to them. In this process, immune boosters such as minerals and vitamins can be very helpful.     

What can weaken the Immune System?

Many factors can influence the strength of the immune system. This is primarily because the immune system is made of so many components. If, for example, there is something wrong with the lymphatic system, the white blood cells, or one of the organs, the immune system will malfunction.

A person is considered immunocompromised if they are affected by any disorders that weakens the immune system. Such disorders can be congenital or acquired during a lifetime due to environmental factors. These factors include:

·       Malnutrition

·       Viral hepatitis

·       HIV infection

·       Some cancer types

·       Certain medical treatments

Immunodeficiency does always have a strong acute onset. It can be present without significant symptoms for a long time, which is why many immunocompromised people are not fully aware of their condition. It is not uncommon for a disease, especially an infection, to uncover the full scale of the problem. 

Symptoms of a Weak Immune System

The immune system is your body’s defense line. The stronger it is the less likely you will experience severe problems with diseases such as viral and bacterial infections. That is why some people can have the flu without any serious symptoms while for others it can be a life-threatening condition.

An immunocompromised person will get sick more often and experience worse symptoms. Infections of different types are the most common problem. During this pandemic those with weakened immune systems need to be especially careful. 

Other symptoms of a weak immune system are:

·       Anemia

·       Digestive problems

·       Development problem is children

·       Inflammation of the internal organs

·       Autoimmune disorders (e.g. eczema, psoriasis, etc.)

The Best Immune System Boosters

A well-balanced diet contains many immunity-boosting components. This can be vitamins, minerals, antioxidants, and other chemical compounds that benefit your health. It is important to know where you can find these immune system boosters in a sufficient amount as well as the best and safest way to use them.

Vitamin C

Vitamin C is a powerful antioxidtant that is known to increase immune function and support the health of cells in the body. It can be found in many fruits and vegetables or can taken in supplment form. Vitamin C is often taken as a supplement to protect against the flu and other infections. This is because there are many medical studies that have proven its ability to boost immunity.

Vitamin C works on a cellular level to provide support for the production of various types of immune cells. This increases the bodies ability to fight against infections. 

Researchers have found a link between vitamin C supplementation and the frequency of respiratory tract infections. Several studies have concluded that regular vitamin C supplementation reduces the duration and severity of common colds in adults as well as children. 

Vitamin C works as a powerful antioxidant to protect the cells from oxidative stress caused by free radicals. Oxidative stress can cause significant damage to the immune system and open the way for many different diseases.

There is some evidence that vitamin C works even better in combination with intense physical activity. A study suggests that vitamin C supplements can reduce the frequency of common colds by 50% in professional athletes and soldiers.

When it comes to infections, vitamin C is not only used as a preventive measure, but also as part of the treatment. When injected intravenously, high doses of vitamin C can greatly improve the symptoms of sepsis, acute respiratory distress syndrome, and other viral infections.

Foods with a high concentration of vitamin C are:

·       Rosehips

·       Chili peppers

·       Guava

·       Blackcurrant

·       Thyme

·       Parsley

·       Kale

·       Kiwi fruits

·       Broccoli

·       Lemons

·       Oranges

Experts recommend a regular daily intake of 250 to 1000mgs of vitamin C, while the upper limit is set at 2000mgs/day.


Zinc is a mineral well-known for its immune system boosting properties and effectiveness in treating the common cold. Because of this, zinc is often added to immunity-boosting healthcare supplements.

In the midst of this corona virus pandemic, scientists are paying extra attention to zinc. There have been several cases showing cholorquine with Zinc as an effection treatment option for those suffring from corona virus. Some doctors are even considering cholorquine with Zinc as more effective than choloquine with azithyomycin due to Zincs impact on the ion chanel in the virus. 

In laboratory conditions, zinc’s effect on respiratoy virsues is well-researched and understood. It has been proven that zinc can reduce the duration and reduce the frequency of respiratory infections due to its ablity to increase the immune system and its determental impact on the cold virus.

Zinc deficiency is rare in the developed world. The main reason for this is easy access to diverse and nutrient-rich foods. In developing countries however, zinc deficiency is an important risk factor for bacterial and viral infections, including pneumonia. Around two billion people worldwide are faced with the lack of this important mineral in their diet.

The recommended daily intake of zinc for healthy, non-pregnant, adults is 11mg per day. The upper limit is set at 40mg/day. Zinc is known to irritate the stomach so it should be always be taken with food.

Good natural sources of zinc are:

·       Beef

·       Pork

·       Lamb

·       Chicken

·       Turkey

·       Oysters

·       Beans

·       Nuts

·       Whole grains

·       Fortified cereals

Regular zinc supplementations can result in certain unwanted side effects. The most common side effect is the loss of smell, which can sometimes be permanent. Taking too much zinc can cause nausea, cough, fever, and can lead to reduced immune function. 


Lysine is an amino acid that has an important role in the biosynthesis of proteins. It also plays a role in strenghtening the immune system and has antiviral properties. During the coronavirus pandemic lysine is a good supplement to take as it is shown to inhibit the proliferation of viruses. 

The role of lysine in the immune system can be observed the best through its support to another highly important immunity booster, zinc. Lysine supports zinc in giving a boost to the cell-mediated immune system. Zinc and lysine supplementation increases serum zinc levels significantly it improves the differentiation of T-lymphocytes cells including CD4.

Studies show that the use of lysine and zinc together reduces the frequency and duration of respiratory infections, including the ones caused by the Influenza virus.

Good dietary sources of lysine are:

·       Beef

·       Chicken

·       Fish

·       Eggs

·       Milk

·       Lentils

·       Kidney beans

·       Navy beans

·       Pea


There are two very important facts about selenium. The first one is that it is an essential mineral. This means that your body needs selenium to function properly. The second important fact is that you can only get selenium through your diet.

The human body needs only small amounts of selenium. However, its importance for various vital processes is very significant.

The role of selenium in the immune system might not be as significant as in thyroid function and metabolism, but it is nonetheless valuable.

Selenium is an antioxidant, it decreases the oxidative stress inside the body. This results in reduced inflammation and improved immune system.

Some research suggests that higher levels of selenium in the blood improve the body’s immune response. It was also found that selenium’s deficiency slows down the immune response and harms the function of the immune cells.

Selenium can boost the immune system and improve the symptoms in patients suffering from different viral infections such as HIV, Hepatitis C, and Influenza.

The best dietary sources of selenium are:

·       Brazil nuts

·       Sunflower seeds

·       Oysters

·       Yellowfin tuna

·       Sardines

·       Chicken breasts

·       Eggs

·       Shiitake mushrooms

As we’ve mentioned earlier, the human body only needs a small amount of selenium. Most of these foods contain a sufficient daily amount in very small quantities. For example, Brazil nuts contain 164% of the recommended daily amount (RDA) in only one nut.

That is why you need to be careful when consuming selenium-rich foods because high doses of selenium can be toxic and produce symptoms such as:

·       Nausea

·       Vomiting

·       Dizziness

·       Facial flushing

·       Muscle soreness

·       Hair loss


Garlic has been associated with many health benefits for millennia. The good news is that this popular belief is also supported by science.

Eating garlic helps the immune system function and it is effective in both prevention and treatment of the common cold (seasonal flu).

Fresh garlic contains a compound called alliin. This derivative of the amino acid cysteine is the reason behind garlic’s distinctive aroma.

When you chew or chop alliin it converts into allicin, a sulfur-containing compound. It is during this process that the well-known smell of garlic is released.

Allicin is very unstable. That is why it easily converts to other sulfur-containing compounds. Many of these are responsible for garlic’s medicinal properties.

The most important of these properties is boosting the disease-fighting response in certain white blood cells during viral infections.

While garlic is certainly helpful in the immune system’s fight against viruses, researchers believe that its preventive properties are even more important.

One study concluded that people who regularly consume garlic have a 63% lower risk of catching a cold and that their colds are 70% shorter. Garlic can also reduce the severity of flu symptoms.

The best way to eat garlic is to chop it or crush it before use. This increases the allicin content. Raw and aged garlic is recommended (at least one clove three times a day), while powder garlic should be avoided as it does not contain allicin.

There are also garlic supplements available. However, make sure not to exceed the recommended dosage as high intakes of garlic’s supplements can be toxic.     

B-complex Vitamins

B-complex vitamins are a group of chemical compounds often found together in the same foods. All together there are eight B-complex vitamins:

·       Vitamin B1 – Thiamin

·       Vitamin B2 – Riboflavin

·       Vitamin B3 – Niacin

·       Vitamin B5 – Pantothenic acid

·       Vitamin B6 – Pyridoxine

·       Vitamin B7 – Biotin

·       Vitamin B9 – Folate

·       Vitamin B12 – Cyanocobalamin

B-complex vitamins play an important role in various metabolic processes, such as the release of energy from carbohydrates, catabolism, oxidation of fatty acids, and the metabolism of glucose, fat, alcohol, etc.

Similar to many other vitamins, B-complex vitamin deficiency can cause various health issues. Probably the best-known disease caused by vitamin B1 deficiency is beriberi. It is a disease that affects the nervous system and can cause pain in the limbs, weakness, irregular heartbeat, weight loss, edema, and heart failure.

The deficiency of other vitamins from the b-complex group can cause an array of health issues ranging from seborrheic dermatitis to acne, insomnia, and anemia.

B12 and B6 vitamins play an important role in healthy immune system response. Certain studies suggest that vitamin B6 supplementation, in large doses, can boost the immune response in critically ill patients.

Unfortunately, vitamins B6 and B12 deficiency is very common in adults and needs to be addressed with a diverse diet or supplementation.

Foods rich in b-complex vitamins include:

·       Animal liver

·       Tuna

·       Turkey

·       Beans

·       Potatoes

·       Whole grains

·       Bananas

·       Nutritional yeast

·       Brewer’s yeast

Contrary to the popular belief, beer is not a good source of vitamin B. The reason for this is alcohol (ethanol) which inhibits the absorption of most B vitamins found in brewer’s yeast.

Since B-complex vitamins are most abundant in meat and foods of animal origin, vitamin B deficiency is a particular concern for vegans.

Vitamin D

Vitamin D, or the sun vitamin as many people know it, is an important nutrient that our body can synthesize. This is good news since vitamin D is pretty scarce in the diet. Only the meat of certain types of fatty fish contains reasonable amounts of this nutrient.

Our skin, more accurately the lower layer of the epidermis, can synthesize vitamin D during sun exposure (UVB radiation exposure). When the exposure to sunlight sparks the chemical reaction in the skin, vitamin D is created as a result.

However, vitamin D is biologically inactive. With the help of certain protein enzymes, vitamin D is activated in the liver and kidneys. Once it is present in a sufficient amount vitamin D plays an important role in the intestinal absorption of magnesium, calcium, and phosphate. It also boosts the immune system.

White blood cells are the most important part of the immune response. On their surface, there are vitamin D activating enzymes and receptors. This shows how much vitamin D is important.

To be perfectly accurate, we can say that vitamin D’s main role is to keep the immune system perfectly balanced. This means avoiding too little or too much immune system activity.

For example, the immune system hyperactivity can trigger autoimmune diseases. On the other hand, if the immune system is not active enough frequent infections will occur.

Low levels of vitamin D have been associated with both, high and low activity of the immune system. Some studies show that low levels of vitamin D can worsen autoimmune diseases although they do not cause them.

Frequent infections are also linked to low levels of vitamin D. The National Institute of Health (NIH) warns that frequent influenza infections, in particular, are connected to low vitamin D levels.

This warning serves as a pretext for many studies about vitamin D’s role in the immune system. Researchers try to understand the connection between the two and determine the best way of supplementation.

Clinical trials from 2017 showed that vitamin D supplements can reduce the frequency of respiratory infections by 42%. They also conclude that a daily or weekly intake of vitamin D is more effective than, previously suggested, large monthly doses.

However, other studies showed that vitamin D supplements are not effective in preventing acute respiratory infections.

From all these, we can conclude that optimal levels of vitamin D are extremely important for a balanced and proper functioning of the immune system. Nevertheless, vitamin D supplements are not necessarily a method of respiratory infection prevention.

Vitamin E

Vitamin E is a common name given to a group of eight fat-soluble compounds with anti-oxidative properties. A balanced diet is normally a good source of vitamin E. That is why vitamin E deficiency is rare in the developed world.

Still, vitamin E deficiency can occur in humans. When this happens, the main cause is usually not the diet. It is rather a consequence of some metabolism abnormality or a problem with dietary fat absorption.

Vitamin E deficiency weakens the immune system and causes nerve problems such as peripheral neuropathy, retinopathy, and myopathy.

Vitamin E is recognized as the immune function modulator. Its concentration in immune cells is significantly higher compared with other cell types found in the blood. Research shows that vitamin E boosts the immune system and lowers the risk of infections, especially in older people.

Vitamin E modulates the immune function by impacting the T cell membrane integrity. By doing this, vitamin E changes the host’s susceptibility to respiratory infections and other bacterial or viral infections.

Some human studies show that a higher vitamin E intake (through supplementation), boosts the function of the immune system. This vitamin seems to be particularly good at improving the age-deteriorated immune response.

Fatty and oily foods are the richest in vitamin E. The best sources include:

·       Sunflower seeds

·       Sunflower oil

·       Peanuts

·       Almonds

·       Avocados

·       Wheat germ oil

·       Hazelnut oil

·       Goose meat

·       Salmon

·       Trout

The main risk associated with the high dietary intake of vitamin E is the overconsumption of animal fat and oils. In high and frequent doses these are proven to be unhealthy for the heart and the cardiovascular system.

When it comes to vitamin E supplementation, extremely high doses can cause side effects such as:

·       Stomach cramps

·       Nausea

·       Diarrhea

·       Headache

·       Blurred vision

·       Fatigue

·       Bruising

·       Bleeding


Your immune system is your first and most important line of defense against all diseases. It is an irreplaceable barrier that protects you from both viral and bacterial infections. Unfortunately, some times the immune system cannot win a fight against the disease on its own, it needs your help. There are many ways in which you can help your immune system. A regular intake of immunity-boosting foods and supplements is probably the best of these. In this article, we described the most powerful, scientifically proven immune system boosters.

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