In 2020, a global pandemic thrust the issue of immunity into the limelight. Many of us were left wondering how to boost our natural defenses and reduce the risk of infection. Aside from precautions like handwashing and mask-wearing, supporting immune health became a top priority.
Optimizing immune function is the best way to protect ourselves from harmful viruses, bacteria, and other pathogens. But it is also much more than that. In many cases, having a healthy immune system could delay or prevent the onset of chronic conditions like cancer. Therefore, it is essential to do all we can to support it, regardless of the threat of infection.
That said, immunity is a complex subject, and an overactive immune system can be as detrimental as an underactive one. Excessive immune responses can cause allergies, in which the body reacts to harmless stimuli as if they were dangerous. Meanwhile, autoimmune disorders cause the immune system to attack the body’s cells leading to inflammation, tissue damage, and disease.
Therefore, keeping the immune system in balance can be challenging for some. The good news is that healthy eating, regular exercise, managing stress, and getting enough sleep can all help. Some people also recommend taking immune system-boosting vitamins and minerals to complement these beneficial activities.
This article explores whether these “immunity vitamins” are truly effective and which supplements are worth consideration. Here’s all you need to know.
Immune System Boosting Vitamins and Minerals
The immune system comprises various structures, cells, and chemicals that work together to protect the body from infection and disease.
The skin, body hair, and mucous membranes are our first line of defense, providing physical barriers against harmful microbes like viruses and bacteria. Chemicals like stomach acid and the enzymes in saliva, sweat, and tears act as an additional shield.
If a pathogen does make it into the body, chemical messengers called cytokines raise the alarm. Blood flows to the area, bringing a host of white blood cells designed to destroy the invaders and neutralize the threat.
This early warning system results in inflammation. It is why an injured area becomes red and swollen, or we develop a sore throat when we catch a cold. Many people view inflammation negatively, but it is a natural and necessary part of the immune response. It is only when the inflammatory process fails to switch off appropriately that problems occur.
All of the above components contribute to what is known as innate immunity. It is our in-built defense system and becomes active as soon as we are born.
We also have adaptive (or acquired) immunity that develops throughout our lives. It is the ability to recognize pathogens that have infected us previously and mount a rapid response. It relies upon proteins called antibodies that help our immune cells remember microbes they have encountered before.
Many different factors influence our innate and adaptive immune functions. Some of these factors cannot be controlled, such as age or chronic disease. However, others can, including sleep, stress, exercise, and diet.
Adequate nutrition is essential, and many micronutrient deficiencies have been linked with impaired immunity. So, what are the most important immune system vitamins and minerals? Let’s take a look.
Best Vitamins for Immune System Health
Vitamin C is indispensable for immune support, and it has several crucial functions.
Firstly, this micronutrient has an essential role in collagen production. Collagen is the protein that keeps skin strong and supple. Therefore, vitamin C directly influences skin health and helps to maintain its barrier integrity.
It is also necessary for the growth and development of T and B cells. T cells are responsible for recognizing foreign particles, and B cells produce antibodies. This function makes vitamin C important for both innate and adaptive immunity.
The vitamin also promotes inflammatory signaling, encouraging white blood cells to travel to infected areas. Meanwhile, its potent antioxidant effects help to protect tissues from damage.
Studies have shown that vitamin C deficiency increases one’s susceptibility to respiratory infections like colds and flu. There is also evidence that supplementation could reduce the risk of developing severe complications like pneumonia.
Food sources: Citrus fruits, bell peppers, strawberries, leafy greens.
Vitamin D is another essential nutrient for immune health.
It appears to improve immune function by enhancing barrier integrity and increasing white blood cell activity. It strengthens innate and adaptive immunity and protects against viral infections.
There are vitamin D receptors throughout the body, including T cells, B cells, and the lining of the lungs. It seems that mutations in the genes responsible for generating these receptors can increase the risk of respiratory infections. Furthermore, low vitamin D levels are associated with more frequent and severe infections.
There is some evidence to support supplementation for preventing and treating respiratory infections and tuberculosis. Supplements may also help other respiratory conditions like asthma and chronic obstructive pulmonary disease (COPD).
Furthermore, vitamin D has immunomodulatory and anti-inflammatory effects, making it potentially useful for autoimmune disorders.
Sources: Sunlight on the skin, fatty fish, beef liver, egg yolks, UV-exposed mushrooms.
Vitamin A plays a role in inflammation, immunomodulation, and autoimmune disorders. It is necessary for the normal development of immune cells and the tissues that line the digestive system and lungs.
Deficiencies are associated with impaired barrier function, abnormal immune responses, and an increased risk of infection.
Research suggests that vitamin A could also protect against specific viral infections, including hepatitis B, influenza, norovirus, and more. It also appears that supplements could reduce the risk of infection-related deaths occurring in association with vitamin A deficiency.
Food sources: Fatty fish, beef liver, eggs, leafy greens, bell peppers, tomatoes, and other brightly colored fruits and vegetables.
Vitamin B6 (Pyridoxine)
The B vitamins have many crucial functions, including energy metabolism, cell function, and DNA synthesis. B6, in particular, affects innate and adaptive immunity by influencing the development of immune cells. It also supports white blood cell activity, alongside vitamins B9 and B12.
Food sources: Meat, poultry, legumes, nuts.
Vitamin B9 (Folate or Folic Acid)
Vitamin B9 (folate or folic acid) is heavily involved in DNA synthesis. This makes it essential for the healthy development of immune cells.
Vitamin B9 (and B12) deficiencies are associated with lower-than-average levels of glutathione, the body’s master antioxidant. Therefore, people lacking this nutrient may be more susceptible to the harmful effects of free radicals generated by the inflammatory response.
Food sources: Leafy greens, citrus fruits, nuts, legumes.
Vitamin E is another nutrient with antioxidant effects and the ability to protect cells from damage. It is also involved in immune cell signaling and affects the activity of several types of immune cells.
Animal studies have demonstrated links between vitamin E deficiency and impaired immune function. There is also a suggestion that supplementation could increase resistance to infections, although human research is limited.
Food sources: Vegetable oils, nuts and seeds, leafy greens, avocados, bell peppers, asparagus, mangos.
Zinc is among the most important minerals for immune health and is often found in immunity-boosting supplements.
This micronutrient can enhance or inhibit specific immune functions, balancing pro-inflammatory and anti-inflammatory effects. Zinc deficiencies have been linked with the overproduction of pro-inflammatory cytokines.
Other key functions include maintaining barrier integrity and regulating T and B cell numbers. The mineral also has some direct antiviral effects. For example, it inhibits an enzyme that certain viruses need to replicate.
There is evidence that zinc supplements could help prevent respiratory infections or shorten their duration.
Food sources: Meat, poultry, shellfish, whole grains, nuts, legumes.
Selenium is another crucial mineral for immune function.
It helps to modulate inflammation, and animal studies suggest it increases cellular immunity by enhancing T cell function. It may also have some direct antiviral effects.
Selenium deficiencies have been associated with impaired innate and adaptive immunity, including reduced T and B cell function, decreased antibody production, and increased susceptibility to infection.
Food sources: Meat, fish, shellfish, eggs, legumes, nuts (especially Brazil nuts).
Copper supports the activity of white blood cells, T cells, and B cells. It also has some direct antimicrobial effects.
Copper deficiencies have been linked with an increased risk of infection.
Food sources: Beef liver, shellfish, whole grains, nuts and seeds, mushrooms, avocados, tofu.
Iron influences cell development, including immune cells. It also has antibacterial effects and can increase the activity of some white blood cells. Furthermore, iron deficiencies are associated with atrophy of the thymus gland, the organ that produces T cells.
However, consuming too much iron may be detrimental. The mineral acts as fuel for some pathogens and could increase the severity of certain infections. Iron overload can also impair overall immune function and promote excess inflammation.
Food sources: Lean red meat, eggs, leafy greens, whole grains, dried fruit.
Supplements to Boost Immune System Health
Supplements are not always necessary for immune health, and many people can meet their nutrient requirements by eating a balanced diet. However, not everyone can get enough nutrition from food, and people with specific micronutrient deficiencies may need extra help.
Fortunately, there are plenty of immunity vitamins on the market. Many are little more than a general multivitamin, while others contain immunity-specific vitamins and minerals. The strongest evidence for supplementation relates to vitamin C, vitamin D, and zinc. However, all of the micronutrients listed above may prove beneficial.
Some products contain other ingredients like echinacea, elderberry, or probiotics. All of these may have some benefits for immunity, although the evidence supporting their use is inconclusive. Furthermore, products containing echinacea should not be used long-term.
There is also a growing trend toward using mushroom supplements to boost immunity. Mushrooms contain complex carbohydrates called beta-glucan polysaccharides, which appear to benefit the immune system in several ways.
Whenever choosing a supplement, it is essential to conduct thorough research before purchasing. This includes ensuring that the brand is reputable and reliable and that the specific product is suitable for you. We recommend consulting a dietician or physician before taking any supplement for the first time.
Minerals and Vitamins for Immune System Health: Summary
Eating well, exercising regularly, managing stress, and getting enough sleep can all contribute to a healthy immune system. Diet is especially important as micronutrient deficiencies can impair immunity significantly.
Older adults and individuals with chronic conditions may be more prone to deficiencies than others. These people may benefit from taking supplements containing the immune system-boosting vitamins listed above.
These products are not a magic bullet but using them alongside other activities that support your immune system could help. However, it is best to consult a professional to ensure that you choose the most appropriate supplement for you.