The 15 best immune-boosting vitamins

Deficiencies in certain vitamins, including vitamin C, zinc, and others, can weaken your immune system. Supplementing with these nutrients may help support immune system function.

Your immune system consists of a complex collection of cells, processes, and chemicals that continuously protect your body against invading pathogens, including viruses, toxins, and bacteria. Maintaining a healthy immune system year-round is essential for preventing infections and illness.

The most important way to strengthen the immune system is to maintain a healthy lifestyle by eating nutritious foods, getting enough sleep, and exercising.

In addition, research has shown that supplementing with certain vitamins, minerals, herbs, and other substances may help improve the immune response and potentially protect against illness.

However, keep in mind that some supplements may interact with prescription or over-the-counter medications you are taking. Some may not be suitable for people with certain health conditions. Be sure to speak with a healthcare professional before starting any supplement.

Here are 15 supplements known for their immune-boosting potential.

1. Vitamin D

Vitamin D is a fat-soluble nutrient that is essential for the health and function of the immune system.

Vitamin D enhances the pathogen-fighting effects of monocytes and macrophages—white blood cells that are an important part of immune defense—and reduces inflammation, which helps promote the immune response.

Many people are deficient in this important vitamin, which can negatively affect immune function. In fact, low vitamin D levels have been associated with an increased risk of upper respiratory tract infections, including influenza and allergic asthma.

Some studies suggest that vitamin D supplementation may improve the immune response. Moreover, recent research suggests that taking this vitamin may protect against respiratory infections.

According to a 2019 review of randomized controlled trials involving 11,321 people, vitamin D supplementation significantly reduced the risk of respiratory infections in people who were deficient in this vitamin and reduced the risk of infection in those with adequate vitamin D levels.

This refers to a general protective effect. Other studies suggest that vitamin D supplements may improve the response to antiviral treatments in certain infections, including hepatitis C and HIV.

Depending on blood levels, supplemental vitamin D in amounts ranging from 1,000 to 4,000 IU per day is sufficient for most people, although those with more severe deficiencies often need much higher doses.

Vitamin D has been widely studied in connection with COVID-19 because of its effects on the immune system. Studies have shown that vitamin D may speed recovery and stop inflammation in the respiratory system.

However, many experts within the medical and scientific communities maintain that vitamin D supplementation is generally safe and may help protect individuals from the virus.

SUMMARY Vitamin D is essential for immune system function. Healthy levels of this vitamin may help reduce the risk of respiratory infections.

2. Zinc

Zinc is a mineral often added to dietary supplements and other health products, such as lozenges intended to boost the immune system. Zinc is essential for immune system function.

Zinc is required for the development and communication of immune cells and plays an important role in the inflammatory response. Zinc also specifically protects tissue barriers in the body and helps prevent foreign pathogens from entering.

A deficiency in this nutrient significantly impairs the immune system's ability to function properly, resulting in an increased risk of infections and illnesses, including pneumonia.

Research suggests that 16% of lower respiratory tract infections worldwide can be attributed to zinc deficiency.

Zinc deficiency affects approximately 2 billion people worldwide and is very common among older adults. In fact, up to 30% of older adults may be considered deficient in this nutrient.

Zinc deficiency is relatively rare in North America and developed countries.

Nevertheless, many individuals in the United States have marginal zinc deficiency, which is related to intake or

is related to absorption. Older individuals are generally at increased risk.

Numerous studies have shown that zinc supplements may protect against respiratory infections, such as the common cold.

Moreover, zinc supplementation may benefit people who are already sick.

In a 2019 study of 64 children hospitalized with acute lower respiratory tract infection (ALRI), taking 30 mg of zinc daily reduced the total duration of the infection and the length of hospital stay by an average of 2 days compared with the placebo group.

Supplemental zinc may also reduce the duration of the common cold. In addition, zinc has demonstrated antiviral activity.

Long-term zinc supplementation is generally safe for healthy adults, provided that the daily dose does not exceed the established upper limit of 40 mg of elemental zinc.

Excessive doses may interfere with copper absorption, which can increase the risk of infection.

SUMMARY Zinc supplementation may help protect against respiratory infections and reduce their duration.

3. Vitamin C

Because of its important role in immune system health, vitamin C may be the most popular supplement taken to help protect against infections.

This vitamin supports the function of various immune cells and enhances their ability to defend against infections. It is also necessary for cell death, which helps maintain immune system health by clearing out old cells and replacing them with new ones.

Vitamin C also acts as a powerful antioxidant, protecting against damage caused by oxidative stress, which involves the accumulation of reactive molecules known as free radicals.

Oxidative stress can negatively affect immune system health and is associated with numerous diseases.

Vitamin C supplementation has been shown to reduce the duration and severity of upper respiratory infections, including the common cold.

A large review of 29 studies involving 11,306 people found that regularly supplementing with vitamin C at an average dose of 1–2 grams per day reduced the duration of colds by 8% in adults and 14% in children.

Interestingly, the review also found that regularly taking vitamin C supplements reduced the incidence of colds by up to 50% in individuals exposed to intense physical stress, including marathon runners and soldiers.

4. Elderberry

Black elderberry (Sambucus nigra), which has long been used to treat infections, is being studied for its effects on immune system health.

Elderberry extract has shown strong antibacterial and antiviral potential in test-tube studies against bacterial pathogens responsible for upper respiratory infections and strains of the influenza virus.

Moreover, it has been shown to enhance the immune system’s response and may help shorten the duration and severity of colds, as well as reduce symptoms associated with viral infections.

A review of 4 randomized controlled trials involving 180 people found that elderberry preparations significantly reduced upper respiratory symptoms caused by viral infections.

An older, 2004, 5-day study found that people with the flu who took 1 tablespoon (15 mL) of elderberry syrup 4 times daily experienced symptom relief 4 days earlier than those who did not take the syrup and were less likely to require medication.

However, this study is outdated and was sponsored by the manufacturer of elderberry syrup, which may bias the results.

Although elderberry may help relieve the symptoms of certain infections and influenza viruses, we must also be aware of the risks. Some reports suggest that elderberry may lead to excessive cytokine production, which could potentially damage healthy cells.

A systematic review of elderberry reached the following conclusion:

• In laboratory animal studies and human research, elderberry demonstrated antiviral effects, inhibiting numerous strains of influenza A and B.
• Raw elderberries must be cooked to avoid the risk of nausea, vomiting, or cyanide poisoning.
• Elderberries should only be used under the guidance of a qualified healthcare professional.
• Elderberry supplements are most commonly sold in liquid or capsule form.

SUMMARY Taking elderberry supplements may help reduce upper respiratory symptoms caused by viral infections and relieve flu symptoms. However, elderberry also carries risks. More research is needed.

5. Medicinal mushrooms

Medicinal mushrooms have been used since ancient times to prevent and treat infections and diseases. Numerous medicinal mushroom species have been studied for their immune-boosting potential.

More than 270 recognized medicinal mushroom species are known to have immune-boosting properties.

Cordyceps, lion’s mane, maitake, shiitake, reishi, and turkey tail are all types that have been shown to benefit immune system health.

Some research suggests that supplementing with certain medicinal mushroom species may enhance immune system health in several ways and reduce the symptoms of certain conditions, such as asthma and lung infections.

For example, a study in mice with tuberculosis, a serious bacterial disease, found that cordyceps treatment significantly reduced the bacterial load in the lungs, enhanced the immune response, and reduced inflammation compared with the placebo group.

In a randomized, 8-week study of 79 adults, supplementation with 1.7 grams of cordyceps mycelial culture extract resulted in a significant 38% increase in natural killer (NK) cell activity, a type of white blood cell that protects against infections.

Many other medicinal mushrooms have also been studied for their beneficial effects on immune system health. Medicinal mushroom preparations are available in the form of tinctures, teas, and dietary supplements.

SUMMARY Numerous medicinal mushroom species, including cordyceps and turkey tail, may have immune-boosting and antibacterial effects.

6–15. Other supplements with immune-boosting potential

In addition to those listed above, numerous dietary supplements may help improve the immune response:

• Astragalus. Astragalus is a herb commonly used in traditional Chinese medicine (TCM). Animal studies suggest that its extract may significantly improve immune-related responses.
• Selenium. Selenium is a mineral essential for immune system health. Animal studies show that selenium supplementation may enhance antiviral protection against influenza strains, including H1N1.
• Garlic. Garlic has powerful anti-inflammatory and antiviral properties. It has been shown to support immune system health by stimulating protective white blood cells, such as NK cells and macrophages. However, human research is limited.
• Andrographis. This herb contains andrographolide, a terpenoid compound that has been found to have antiviral effects against viruses that cause respiratory illnesses, including Enterovirus D68 and influenza A virus.
• Licorice root. Licorice root contains several compounds, including glycyrrhizin, that may help protect against viral infections. According to test-tube studies, glycyrrhizin has antiviral effects against the coronavirus associated with severe acute respiratory syndrome (SARS-CoV).
• Pelargonium sidoides. Some human studies support using extracts of this plant to alleviate the symptoms of acute viral respiratory infections, including the common cold and bronchitis. However, the results are mixed, and further research is needed.
• B-complex vitamins. B vitamins, including B12 and B6, are important for a healthy immune response. Yet many adults are deficient in them, which can negatively affect immune system health. Curcumin. Curcumin is the main active compound in turmeric. It has powerful anti-inflammatory properties, and animal studies suggest it may help improve immune system function.

SUMMARYMany dietary supplements available on the market may help improve immune system health.

Zinc, elderberry, and vitamins C and D are just some of the substances whose immune-supporting potential has been studied.

However, although these supplements may slightly improve immune system health, they should not—and cannot—be used as a substitute for a healthy lifestyle.

A balanced, nutrient-rich diet, sufficient sleep, regular exercise, and avoiding smoking are the most important ways to help maintain immune system health and reduce the likelihood of developing infections and illnesses.

If you decide you would like to try a dietary supplement, speak with a healthcare professional first.

Source: www.healthline.com