A strong immune system is key to preventing infection and disease. While getting enough sleep
, and eating nutritious foods
are essential for a healthy immune system, research shows specific vitamins, minerals, medicinal plants, and even beneficial bacteria can boost immune function and protect against illness. Vitamin C may be the most popular immune-boosting supplement on the market, but it’s certainly not the only one.
So, what are the best supplements to boost immunity? Whether you want to level up your immunity or kick that cold a bit quicker, here are the best science-backed, immunity-enhancing supplements to consider that are not vitamin C.
How to find the best supplements to boost immunity
With so many supplements on the market, it’s virtually impossible to decide which ones you should take, when you need to take them, and what you should take them with. So how do you sort through the noise and find the best supplements to boost immunity, improve sleep, enhance sports performance, and reduce stress?
has significant anti-inflammatory and antioxidant properties that play an essential role in immune function and support a healthy immune system [1
]. Despite its importance, roughly half of the world’s population (and 90% of new Elo members) have inadequate vitamin D levels [3
Vitamin D plays an important role in immune function, reducing inflammation and modulating growth and development. As such, low vitamin D levels can reduce immune function and have significant health consequences.
For example, studies show vitamin D deficiency is associated with an increased risk of infection and higher rates of certain autoimmune diseases [4
]. Early research also suggests having optimal vitamin D levels may lower your risk for COVID-19 infection and reduce its severity if you become infected [4
The Recommended Dietary Allowance (RDA) for people between the ages of 1 and 70 is 600 IU/day, and for adults over 70, the RDA is 800 IU/day [10
]. However, a growing body of evidence has found these amounts are too low, particularly if you do not get adequate sun exposure, already have low levels, or have an increased risk for low vitamin D [6
For most, a supplement providing 1,000–2,000 IU/day of vitamin D3 is sufficient to meet most people’s needs; however, individuals with moderate to severe deficiency may need a higher dose [10
Studies show probiotics
, the good bacteria found in your gut and certain fermented foods, support immune health by inhibiting the growth and adhesion of harmful pathogens and enhancing specific immune cells' response [11
In children, probiotic supplementation may reduce the risk of respiratory infections and may also shorten the duration of some viral respiratory illnesses [12
In adults, studies indicate probiotics may enhance the body’s immune response to the flu shot. For example, in one trial, adults given probiotics or prebiotics showed significant improvements in protection against multiple strains, including H1N1, H3N2, and influenza B [13
Probiotics (specifically Lactobacillus rhamnosus GR-1 and L. reuteri RC-14
) may also bolster the body’s immune defenses against urinary tract infections (UTIs) in women [14
The key to choosing the best probiotics to boost immunity is selecting the strain (or strains) that has been proven beneficial for your specific need and making sure your supplement contains an adequate amount of microorganisms.
Not sure which probiotic you should take? Find out with Elo’s 1:1 dietitian support and Smart Supplements.
Choosing a probiotic supplement can be challenging since strain type and dose size significantly affects whether a probiotic will have any benefit. The key to choosing the best probiotic for immune health is selecting the strain (or strains) that have been proven beneficial for this purpose.
For flu-fighting benefits, Lactobacillus casei, L. paracasei, and Bifidobacterium longum seem to be the most effective of the strains studied.
For UTIs, Lactobacillus rhamnosus GR-1 and L. reuteri RC-14 seem effective.
A daily dose of 1 billion Lactobacillus GG may reduce the risk of respiratory infections in children.
Many probiotic supplements contain 1 to 10 billion CFU per dose, whereas some products contain 50 billion or more. While it’s crucial your supplement contains enough live microbes to be effective, higher CFU counts do not necessarily produce greater health benefits [42
Medicinal mushrooms have incredible health benefits and can be a supportive sidekick for your immune system. Five fungi, in particular, have been shown to have the following immune-boosting benefits.
Reishi mushrooms (Ganoderma lucidum
) have long been used in Eastern medicine to promote health and longevity [15
]. Studies show Reishi mushrooms may boost the immune system and even fight cancer [16
Maitake mushrooms have also been used in Eastern medicine to promote immune function for centuries. Research suggests these mighty mushrooms might play a role in healthy immune function and cancer prevention [18
Turkey tail mushrooms contain a potent compound called polysaccharide-K that gives this fungus its high antioxidant and anti-cancer properties. Research suggests it may also improve the immune system of those receiving chemotherapy [20
Studies show Chaga mushrooms are packed full of antioxidants that can help reduce oxidative stress and inflammation, which negatively affect the immune system [21
]. Preliminary studies in mice suggest Chaga may also help prevent some forms of cancer, but more studies are needed to see if the benefits also apply to humans [23
Shitake mushrooms also appear to play a role in immunity. One study found that people who consumed two dried shiitakes each day experienced a decrease in inflammation and an increase in immune markers [25
When choosing medicinal mushroom supplements, in capsule or powder form, which you can add to teas, smoothies, or soup broth.
Dosing recommendations vary widely between mushroom varieties, supplement forms, and brands. For this reason, it’s recommended you read supplement labels and follow dosing recommendations closely.
Black elderberry (Sambucus nigra) has long been used to treat infections and is being investigated for its effects on immune health.
This unique berry extract has potent antibacterial and antiviral properties, particularly against pathogens responsible for upper respiratory infections. Studies have found it may be beneficial for treating respiratory infections, potentially shortening the duration and severity of colds and reducing respiratory symptoms [27
Compared to oseltamivir (Tamiflu), elderberry may also be associated with a lower risk of influenza complications and adverse events [29
There is no standard dosing recommendation for elderberry. For immune benefits against the flu, some studies have found benefits with 4 tablespoons of elderberry extract syrup divided into four doses [46
Elderberry supplements appear to be safe when used daily for up to 5 days; however, its long-term safety is unknown [46
is a mineral that’s long been known to boost your immune system. It is essential in immune cell development, communication, and the body’s inflammatory response and also protects tissue barriers that prevent harmful pathogens from entering the body [30
Like vitamin D, not getting enough zinc can significantly reduce immune function and increase the risk of infection and disease, including pneumonia [31
Several studies also show zinc supplements may also protect against and reduce the duration of some respiratory tract infections like the common cold [33
Taking 5–10 mg/day of zinc appears adequate as a daily preventive. If you are at risk for, or have a zinc deficiency, a higher dosage of 25-45 mg/day might be necessary [45
Zinc lozenges taken to reduce symptoms of the common cold appear to be most effective when the daily dose is over 75 mg and is divided over 6-8 doses, each separated by 2-3 hours. Because this dose is higher than the 40 mg Tolerable Upper Limit of zinc, prolonged intake of large amounts of zinc from supplements or lozenges is likely unsafe [45
Though it may get a bad rap for giving you stinky breath, garlic has powerful anti-inflammatory and antiviral properties that may also enhance immune function.
Research shows this health-boosting bulb has antiviral, antifungal, and antibacterial properties and may also stimulate protective immune cells and help reduce the severity of cold and flu symptoms [36
Powdered garlic, aged garlic extract, and garlic oil are three common forms of garlic supplements.
Research suggests aged garlic extract may offer the greatest health benefits. Studies looking at the immune benefits of aged garlic extract have found benefits at dosages ranging from 500 mg to 2,560 mg/day [44
Garlic supplements can be toxic in very high amounts, so be sure not to exceed supplement dosage recommendations.
Best known for its anti-inflammatory effects, turmeric
can also help bolster immunity.
Studies show curcumin, turmeric’s primary bioactive compound, can modulate the activation of key immune cells, including T cells, B cells, macrophages, neutrophils, natural killer cells, and dendritic cells. At low doses, curcumin can also enhance antibody response. [38
Curcumin can also reduce the expression of various proinflammatory cytokines that are largely responsible for the development of chronic inflammation [38
]. Chronic inflammation can impair normal immune function, increase susceptibility to infections and tumors, and even produce poor vaccine response in individuals; therefore, keeping inflammation at bay is critical to support immune health [40
Turmeric supplements are available in different dosages and contain varying amounts of curcumin. For instance, studies have shown that supplements that provide 500-1,500 mg of curcumin/day have been associated with numerous benefits related to inflammation and a healthy immune system [41
Sleep, exercise, and a healthy diet are foundational to a healthy immune system. Still, significant research shows certain vitamins, minerals, medicinal plants, and even good bacteria can support immune health. From vitamin D and probiotics, to medicinal mushrooms, elderberry, zinc, garlic, and curcumin— our expert dietitians at Elo Health can help you determine which supplements might give you the biggest immune boost.
Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose, or replace personalized medical care.