The 6 Best Immune Supporting Supplements, According to a Dietitian

Theralogix Thera-D provides 2,000 IU of D3 and is NSF contents certified

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Best Supplements for Immunity According to a Dietitian

Amazon, Thorne

A strong immune system can help you ward off illnesses and recover more quickly. Eating a well balanced diet including a variety of fruits and vegetables, whole grains, nuts and seeds, protein-rich foods, and probiotic-rich foods is key to a healthy immune system. It’s also important to engage in other health-promoting habits, including getting regular exercise (balanced with adequate rest), managing stress, and getting seven to eight hours of sleep per night

“While a supplement can help if you're falling short in any of these areas, doing your best to meet these basic needs is most important,” says Kelsey Lorencz, RDN. Certain nutrients, such as vitamins C and D as well as zinc, are known to play an important role in the immune system,and consuming adequate amounts of these nutrients is essential. While supplements don’t replace a healthy diet, people with elevated nutrient needs or those that have trouble getting enough through diet may benefit from a supplement. 

When choosing a supplement to support your immune system, consider any nutrient gaps you might have and prioritize those. It’s also important to look for supplements that are third-party tested and be mindful of dosing, as many immune supporting supplements come in mega-doses that may not be safe. Importantly, if you are taking other supplements or medication or have any underlying medical condition, always check with a healthcare provider before starting a new supplement since some immune supporting supplements can interact with medications and other supplements.

Always speak with a healthcare professional before adding a supplement to your routine to ensure that the supplement is appropriate for your individual needs, and to find out what dosage to take.

Best Vitamin D

Theralogix Thera-D 2,000

Thera-D 2,000


  • NSF contents certified

  • Gluten-free and vegetarian

  • Available in multiple doses

  • May be higher dose than some people need

Vitamin D plays an important role in the immune system, and some research suggests that having adequate stores may play a role in reducing severity of the flu and COVID-19. Supplements have also been shown to reduce risk of respiratory infections in people who are vitamin D deficient.

Vitamin D deficiency and insufficiency are common, especially for people who live in parts of the world where year-round sun exposure is not possible. “In the winter months, most of us have a difficult time getting enough vitamin D. There are not a lot of foods that naturally have vitamin D, so unless you're eating and drinking foods that are fortified with this fat-soluble vitamin, getting enough without sun exposure is nearly impossible.” says Lorencz.

We recommend Theralogix Thera-D because it’s NSF contents certified, which means that it contains what the label says and doesn't have any harmful contaminants. It’s also budget-friendly, and comes in three different doses—2,000 IU, 4,000 IU, and 6,000 IU. The right dose for you will depend on your current vitamin D status, which is why we recommend having a healthcare provider check your levels before starting a supplement. 

The recommended dietary allowance (RDA) is 600 IU for most adults, but emerging research suggests we may benefit from higher doses for both maintenance and repletion. One study even found that people who were deficient were able to quickly raise their vitamin D levels to ideal levels with a dose of 10,000 IU per day. These levels help support the immune system and help fight off viruses like the flu and COVID-19. More research is needed, and that level may not be safe for everyone (plus it shouldn’t be taken long-term).

Thera-D is also gluten-free and vegetarian. The lowest available dose is 2,000 IU, which may be more than some people need.

Price at time of publication: $28 for 180 count ($0.16 per serving)

Active nutrients: vitamin D3, calcium | Dose: 2,000, 4,000, or 6,000 IU| Servings per container: 180 | Form: capsule

Best Vitamin C

Klean Athlete KLEAN-C



  • NSF certified for sport

  • Gluten-free and vegan

  • Easy to consume chewable tablet

  • Contains sugar alcohols

Vitamin C is well known for its role in the immune system. While most people consume plenty of vitamin C by eating fruits and vegetables like strawberries, oranges, mango, bell peppers, and sweet potatoes, a supplement may be helpful for some.

Vitamin C supplements aren’t necessarily going to stop you from getting sick, but they could lessen symptoms and help you recover more quickly. “A large review of over 11,000 people found that taking 1,000 to 2,000 milligrams of vitamin C daily reduced the length of a cold by 8% in adults and 14% in kids,” says Lorencz.

If you need a supplement, we recommend KLEAN-C. It’s NSF certified for sport, which ensures that its contents match the label and it doesn’t contain any harmful ingredients or ingredients banned by sport. It contains 525 milligrams of vitamin C along with a very small amount of calcium and sodium. It doesn’t contain additional nutrients that could potentially interact with medications—a common challenge with many vitamin C supplements. It’s also gluten-free and vegan.

The recommended dietary allowance (RDA) for vitamin C is 75 milligrams for women and 90 milligrams for men, but the Tolerable Upper Intake Level (UL) is 2,000 milligrams. KLEAN-C falls well below that limit. It is sweetened with a small amount of sugar alcohols, which can cause digestive upset in some people when consumed in excess.

Price at time of publication: $25 for 60 count ($0.41 per serving)

Active nutrients: vitamin C, calcium, sodium | Dose: 525 milligrams | Servings per container: 60 | Form: chewable tablet

Bes Zinc

Thorne Research Zinc Picolinate, 30 mg

Thorne Research Zinc Picolinate, 30 mg


  • NSF Certified for Sport

  • Zinc is only active ingredient

  • May be a higher dose than you need

Zinc is essential for immune health. Some studies suggest that zinc supplements may reduce severity and length of symptoms from the common cold, but more research is needed. Initial studies also suggest that low zinc levels may increase risk for more severe COVID-19 symptoms. 

However, to-date, there’s insufficient evidence to support regular supplementation for those that get enough through food. So if you choose to supplement while you are sick, you shouldn’t continue supplementation for a long period of time unless a healthcare provider has detected a deficiency.

Zinc is found in a variety of foods including seafood, beef, beans, nuts, whole grains, and dairy, and most people can get enough from food. While it is available in plant-based foods, vegans and vegetarians are at higher risk for deficiency because phytates found in whole grains and beans may reduce the absorption of zinc. It’s also estimated that nearly 30 percent of the elderly population is zinc deficient.

If you’re not getting enough through diet, Thorne Research’s zinc picolinate is a good option. Thorne is a well trusted supplement brand and this product is NSF certified for sport. This supplement also stands out because the dose is below the UL of 40 milligrams (many supplements provide well over that dose), and zinc is the only ingredient. This is especially important because high doses of zinc may lead to gastrointestinal upset and dizziness.

It’s important to note that long term zinc supplementation can lead to a copper deficiency, and zinc supplements may interact with medications including antibiotics, diuretics, and drugs to treat rheumatoid arthritis. Always check with a healthcare provider before starting a zinc supplement.

Active nutrients: zinc | Dose: 30 milligrams | Servings per container: 60 | Form: capsule

Best Echinacea

Vital Nutrients Echinacea Extract

Vital Nutrients Echinacea Extract


  • Contains a dose supported by preliminary research

  • Vegan and no gluten-containing ingredients

  • May need to take multiple doses per day

  • More expensive than other options

Echinacea is an herb often used to treat the common cold. Research on the benefits has shown mixed results, which may be related to inconsistent forms and dosing of the herb. Many studies are also funded by organizations that sell echinacea supplements, which may introduce some bias. 

Some studies have suggested that when taken at the first signs of a cold, echinacea may help reduce the severity and length of symptoms, though other studies have shown no benefit. A review of 29 studies showed that taking it preventatively may lessen the chance of getting an upper respiratory infection (such as a cold), though the data was extremely limited, and most of the studies included in the review actually showed no benefit. In general, it appears to be a safe supplement for most adults when taken in the short-term.

If you choose to take echinacea, we recommend Vital Nutrients Echinacea Extract. There currently is no concrete recommended dose, but the 1,000 milligram dose appears to be safe in the short-term. This supplement has been verified to contain what it says it contains with no harmful contaminants, which is especially important with many herbal supplements.

Echinacea may interact with certain immunosuppressants and can increase the time it takes for your body to metabolize caffeine. There’s no research on long-term safety, so it’s best to use just during the height of cold and flu season. So when you're thinking about braving the cold and throwing on your favorite ice-walking shoes, think about echinacea.

Price at time of publication: $25 for 60 count ($0.41 per serving)

Active nutrients: Echinacea herb extract | Dose: 1,000 milligrams | Servings per container: 30 | Form: capsule

Best B-Vitamin

Nature Made Super B-Complex Softgels

Nature Made Super B-Complex


  • USP verified

  • Gluten-free

  • Budget-friendly

  • May not contain enough B-12 for some

B-vitamins play an important role in the immune system. While there isn’t research to suggest that more is better, inadequate levels can contribute to a weakened immune system. B-vitamins are found in a variety of foods, so as long as you eat a balanced diet and don’t eliminate entire food groups, you can get enough through food. However vegans and some vegetarians are at higher risk for deficiency, especially for vitamin B-12.

If you’re not getting enough through diet, a B-complex supplement can be helpful for closing any gaps. Nature Made Super B Energy Complex contains all eight B-vitamins, is USP verified, and is budget-friendly. While it does contain 6 micrograms (250 percent of the RDA), only a small percentage of vitamin B12 is absorbed from supplements. It’s recommended to take 1,000 to 2,000 micrograms to replete a deficiency, so some people may have to take multiple capsules to get enough.

Price at time of publication: $25 for 160 count ($0.15 per serving)

Active nutrients: B-vitamins | Dose: varies | Servings per container: 160 | Form: softgel

Best Multivitamin

Thorne Basic Nutrients 2/Day

Thorne Research Basic Nutrients 2/Day


  • NSF Certified for Sport

  • Contains recommended immune supporting nutrients

  • Vegan and gluten-free

  • Some nutrients may interact with certain medications

  • More expensive than other options

A multivitamin can be helpful if you have multiple nutrient deficiencies, consume a diet that may be lacking enough essential nutrients, or have higher nutrient needs. Thorne Basic Nutrients 2/Day is a good choice as it includes essential nutrients for immune health including vitamin C and D, all eight B-vitamins, and zinc. 

Thorne’s multivitamin also includes other nutrients that are known to play a role in the immune system such as vitamins A and E as well as selenium and magnesium (though these don’t have enough evidence to support recommending them on their own for immune health). 

As with many Thorne supplements, this one is NSF Certified for Sport, which means that includes what is listed on the label, and is free of unsafe levels of contaminants and substances banned for athletes. It’s also dairy-free, soy-free, gluten-free, and vegan.

Price at time of publication: $27 for 60 count ($0.45 per serving)

Active nutrients: many | Dose: varies | Servings per container: 30 | Form: capsule

Are Immune Supporting Supplements Beneficial?

A healthy lifestyle, including eating a well-balanced diet, managing stress, getting adequate sleep, and regularly moving your body, paired with proper hygiene such as handwashing, is the best line of defense for cold and flu season. However, supplements may play a role in supporting the immune system of certain groups of people, including the following: 

  • People with a known nutrient deficiency. There are nearly a dozen vitamins and minerals that are known to play a role in the immune system. Research suggests the particular importance of vitamins C and D and zinc in supporting immune health. If you aren’t getting enough through diet—or are not getting regular strong sun exposure for vitamin D—a supplement may help support your immune system.
  • People with elevated nutrient needs. Athletes, pregnant and breastfeeding people, and people with medical conditions that increase their vitamin and mineral needs may benefit from a supplement.
  • People who follow a restrictive diet. If you eliminate entire food groups or eat a limited number of foods, you may be at risk for a nutrient deficiency, and a supplement can help close those gaps to support immune health.
  • People with poor nutrient absorption. Certain diseases that affect the digestive tract, such as Crohn’s, colitis, celiac disease, some autoimmune disorders, and more, can affect nutrient absorption leading to deficiencies or insufficiency. Supplements can help boost stores and support overall immune health. 
  • Older adults. Older adults are at higher risk for both severe illness from flu and COVID-19 and risk for nutrient deficiencies such as vitamin D.

Who May Not Benefit from Immune Supporting Nutrients?

  • People who eat a balanced diet. If you eat a variety of foods, including fruits, vegetables, whole grains, and protein-rich foods, taking supplements may not actually provide any benefit. The one exception may be vitamin D, since it’s found in a limited number of foods and it can be difficult to get enough through diet alone.
  • People with autoimmune disease. “Some supplements that help to boost the immune system should not be taken by people who have any sort of autoimmune disease. In many autoimmune diseases, the immune system is already overactive, attacking even healthy cells, and adding supplements that heighten the immune response can make problems worse,” says Lorencz. If you have an autoimmune condition, talk to a healthcare provider before starting a supplement.
  • People with certain underlying medical conditions. While those who are immunocompromised may be at heightened risk for more severe viral illnesses, it doesn’t mean you should definitely take a supplement. Supplements with high doses of nutrients may make problems worse, so always check with a healthcare provider to determine if one is appropriate for you.

Supplements that May or May Not Support Your Immune System

  • Elderberry. To date, the research on elderberry extract’s ability to prevent colds or the flu or lessen the severity of symptoms is mixed. Some studies suggest it may slightly lessen the length and severity of symptoms, while others have shown no benefit. Elderberry is Generally Recognized as Safe (GRAS) by the Food and Drug Administration (FDA), though little is known about safety during pregnancy.
  • Probiotics. Emerging research suggests a connection between gut health and immunity. Initial studies suggest that probiotics may provide additional immune support, though more research is needed to understand the strain, dose, and timing of probiotics in relation to cold and flu season. There are dozens of strains, and choosing a probiotic is highly individual. Some probiotics may worsen digestive symptoms of people with underlying digestive disorders or introduce new symptoms to otherwise healthy people. Until we have more research, it’s best to focus on probiotic-rich foods like yogurt, kefir, sauerkraut, and kimchi to support gut health. 

How We Select Supplements 

Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here

We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products.

It's important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.

What to Look For 

Third-Party Testing

Supplements that are third-party tested are sent to a lab where they are tested to ensure they contain what they say they contain and are not contaminated with specific high-risk, common contaminants. However, it’s important to note:

  • Third party testing does not test to see if a product is effective or safe for everyone, and it does not ensure the supplement will not interact with other supplements or medications.
  • Not all third-party testing is created equal. It is not uncommon for supplement companies to pay labs for certificates after conducting minimal to no testing. 
  • The third party certifications we can trust are:, NSF, and USP. However, these certifications are difficult to obtain and/or expensive for manufacturers, so many companies choose not to get their products tested by one of these three organizations. 
  • Sometimes products tested by these three companies are more expensive to try to offset the cost they pay for certification.
  • Just because a supplement is not tested by one of these three companies, it does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer, and calling up the manufacturer and their testing lab to determine their protocols and decide if you feel comfortable consuming the supplement.


The best form will vary by supplement. Please review each of the individual supplement recommendations for the form we recommend. 

Ingredients & Potential Interactions 

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included, relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.

Many supplements that are marketed as immune-supporting contain additional ingredients like herbs, antioxidants, or probiotics that may interact with medications or make certain conditions worse. In general, it’s best to choose supplements that contain just the nutrient you’re looking to replete (such as vitamin D or zinc) rather than combination supplements. The exception to this may be if you can benefit from more than one nutrient, in which case choosing a multivitamin may be helpful. 

Immune Supporting Nutrient Dosage 

The recommended dose varies by supplement. Please review the recommended dosing within each individual supplement review. 

How Much is Too Much? 

It’s important to ensure that you don’t exceed the upper limit as established by the National Institute of Health Office of Dietary Supplements

Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here

Supplements are available in various forms, such as capsules, tablets, lozenges, and liquids. If you have trouble swallowing pills, you may prefer a chewable tablet or liquid supplement.

There are many different types of each supplement available. For example, there is a huge variety of probiotic strains, three species of echinacea, and multiple forms of zinc. Speak with your physician to figure out what works best for you.

It's important to note that these evidence-based supplements may optimize and bolster your immunity; however, it's always a good idea to check with your physician before adding any supplement to your routine. Specifically, ask your health care provider about the supplement and dosage that is right for you.

Frequently Asked Questions

  • Are there foods that help boost immunity?

    A well-balanced diet can support immunity by giving you the nutrients you need to build your immune system. This includes vitamin C, B-vitamins, and zinc. No one food will boost your immunity, rather focus on emphasizing fruits, vegetables, whole grains, and a variety of protein-rich foods like meat, fish, or beans to get the nutrients you need to build a healthy foundation. 

    Probiotic-rich foods such as yogurt, kefir, sauerkraut, or kimchi may also support a healthy gut, which may play a role in immunity, though more research is needed. “Eating foods high in antioxidants like ginger, turmeric, and green tea is a good immune-supporting strategy,” says Lorencz.

  • What are some other ways to keep my immune system strong?

    Diet and supplements are just two of the ways to support your immune system. Getting adequate sleep, managing stress, and participating in regular movement are also the foundation of a healthy immune system.

  • Does protein support the immune system?

    “Yes, protein consists of amino acids, and these amino acids help your body’s T cells, B cells, and antibodies fight infection,” says Amy Gorin, MS, RDN. Many protein-rich foods also contain vitamins that can support your immune system, such as zinc and B-vitamins. It’s important to get enough protein, but getting more than you need won’t supercharge your immune system.

  • What can I do for immune support while I'm pregnant?

    Supporting your immune system while pregnant is not that different than when you’re not pregnant. The foundation lies in your lifestyle. This includes eating a balanced diet that includes a wide variety of foods (especially fruits and vegetables), getting adequate sleep, managing stress, and moving your body in ways that feel good and are safe for your pregnancy. It’s also important to take a prenatal multivitamin while pregnant. Choose one that includes the basics as well as immune-supporting nutrients like vitamin C, vitamin D, zinc, and B-vitamins (which most quality prenatals will include). 

    It’s important to note that the safety of echinacea and other herbs is not known during pregnancy.

  • How can I tell if a product advertising immune support will work?

    Supplements that are marketed to support immunity are not guaranteed to work. Look for supplements that we’ve reviewed and included in this article, and focus on ones that you know will specifically fill gaps in your diet. “You also want to check that the supplement company conducts third-party testing, such as from NSF International,” says Gorin. This ensures the product contains what the label says without potentially harmful contaminants. Otherwise, you may be getting more or less of a nutrient than you think, which could impact its effectiveness.

28 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. NIH News In Health: Do you need dietary supplements?

  2. Grant WB, Lahore H, McDonnell SL, et al. Evidence that vitamin d supplementation could reduce risk of influenza and covid-19 infections and deathsNutrients. 2020;12(4):988. doi:10.3390/nu12040988

  3. Martineau AR, Jolliffe DA, Greenberg L, et al. Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysisHealth Technol Assess. 2019;23(2):1-44. doi:10.3310/hta23020

  4. Parva NR, Tadepalli S, Singh P, et al. Prevalence of vitamin d deficiency and associated risk factors in the us population(2011-2012)Cureus. 2018;10(6). doi:10.7759/cureus.2741

  5. Singh G, Bonham AJ. A predictive equation to guide vitamin d replacement dose in patientsJ Am Board Fam Med. 2014;27(4):495-509. doi:10.3122/jabfm.2014.04.130306

  6. Hemilä H, Chalker E. Vitamin C for preventing and treating the common coldCochrane Database Syst Rev. 2013;(1):CD000980. doi:10.1002/14651858.CD000980.pub4

  7. Office of dietary supplements - vitamin c. National Institute of Health

  8. Mäkinen KK. Gastrointestinal disturbances associated with the consumption of sugar alcohols with special consideration of xylitol: scientific review and instructions for dentists and other health-care professionals. Int J Dent. 2016;2016:5967907. doi:10.1155/2016/5967907

  9. Office of dietary supplements - zinc. National Institute of Health

  10. Vogel-González M, Talló-Parra M, Herrera-Fernández V, et al. Low zinc levels at admission associates with poor clinical outcomes in sars-cov-2 infection. Nutrients. 2021;13(2):562. doi:10.3390/nu13020562 

  11. Foster M, Chu A, Petocz P, Samman S. Effect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans: Zinc and vegetarian diets. J Sci Food Agric. 2013;93(10):2362-2371. doi:10.1002/jsfa.6179

  12. Duncan A, Yacoubian C, Watson N, Morrison I. The risk of copper deficiency in patients prescribed zinc supplements. Journal of Clinical Pathology. 2015;68(9):723-725.

  13. Jawad M, Schoop R, Suter A, Klein P, Eccles R. Safety and efficacy profile of echinacea purpurea to prevent common cold episodes: a randomized, double-blind, placebo-controlled trialEvidence-Based Complementary and Alternative Medicine. 2012;2012:e841315. doi:10.1155/2012/841315

  14. David S, Cunningham R. Echinacea for the prevention and treatment of upper respiratory tract infections: A systematic review and meta-analysis. Complement Ther Med. 2019;44:18-26. doi:10.1016/j.ctim.2019.03.011

  15. Echinacea information | mount sinai - new york. Mount Sinai Health System.

  16. Echinacea. NCCIH.

  17. Mikkelsen K, Apostolopoulos V. Vitamin b12, folic acid, and the immune system. Nutrition and Immunity. 2019:103-114. doi:10.1007/978-3-030-16073-9_6

  18. Office of dietary supplements - vitamin b12. National Institutes of Health

  19. Gombart AF, Pierre A, Maggini S. A review of micronutrients and the immune system–working in harmony to reduce the risk of infection. Nutrients. 2020;12(1):236. doi:10.3390/nu12010236

  20. The malabsorption syndrome and its causes and consequences. Published online January 1, 2014:1266-1287.

  21. Office of dietary supplements - vitamin d. National Institue of Health

  22. Office of dietary supplements - vitamin d. National Institue of Health

  23. Macknin M, Wolski K, Negrey J, Mace S. Elderberry extract outpatient influenza treatment for emergency room patients ages 5 and above: a randomized, double-blind, placebo-controlled trial. J Gen Intern Med. 2020;35(11):3271-3277. doi:10.1007/s11606-020-06170-w

  24. Tiralongo E, Wee SS, Lea RA. Elderberry supplementation reduces cold duration and symptoms in air-travellers: a randomized, double-blind placebo-controlled clinical trial. Nutrients. 2016;8(4):182. doi:10.3390/nu8040182

  25. Elderberry. NCCIH.

  26. Porter RS, Bode RF. A review of the antiviral properties of black elder (Sambucus nigra L.) products. Phytother Res. 2017;31(4):533-554. doi:10.1002/ptr.5782

  27. Nutrition C for FS and A. Questions and answers on dietary supplements. FDA. Published online October 26, 2022.

  28. Zheng D, Liwinski T, Elinav E. Interaction between microbiota and immunity in health and disease. Cell Res. 2020;30(6):492-506. doi:10.1038/s41422-020-0332-7