The 7 Best Immune-Boosting Supplements, According to a Dietitian

Support your immune system with these evidence-backed herbs and vitamins

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Our Top Picks

Best Vitamin C: Doctor's Best Vitamin C at iherb.com

"Research suggests that Vitamin C supports the immune system by reducing the severity and duration of colds."

Best Zinc: Thorne Research Zinc Picolinate 15mg at Walmart

"Zinc is shown to support immune cells, and similar to vitamin C, it may also reduce the severity and duration of the common cold."

Best Vitamin D: Nordic Naturals Vitamin D3 1000 IU at Amazon

"Research shows that supplementation with vitamin D3 may be protective against the flu."

Best Elderberry: Gaia Herbs Black Elderberry Syrup at Amazon

"Research shows that elderberry is protective against the flu."

Best Echinacea: Gaia Herbs Echinacea Supreme at vitaminshoppe.com

"Taking echinacea while you're feeling well is thought to reduce the chances of catching a cold."

Best Turmeric: mykind Organics Extra Strength Turmeric at Amazon

"Has been shown to modulate the activation of immune cells, regulate the body's inflammatory reaction to disease and infection."

Best Probiotic: Renew Life Ultimate Flora Probiotic at Amazon

"Probiotics are generally associated with gut health, however, the beneficial bacteria play a huge role in immune function."

A healthy diet, adequate sleep, exercise, hand hygiene, and stress management are all great ways to support the immune system throughout the year, and especially during cold and flu season. While there are no cure-all supplements or foods—some research studies support the use of specific herbs and vitamins to boost immunity. You may already have some of these—like probiotics, vitamin D, and vitamin C—in your medicine cabinet.

Here, the best immune-boosting supplements.

Our Top Picks

Best Vitamin C: Doctor's Best Vitamin C

Doctor's Best Vitamin C
Courtesy of Doctor's Best.

Research published in 2017 suggests that Vitamin C supports the immune system by reducing the severity and duration of colds. The powerful antioxidant is shown to alleviate and prevent infections caused by bacteria and viruses. This commonly used supplement is a well-known family favorite for boosting immunity year-round.

Doctor's Best Vitamin C provides 1,000 mg of ascorbic acid, which is the preferred source of supplemental vitamin C due to bioavailability. Doctor's Best uses a particular brand of ascorbic acid called Quali-C, which is celebrated for its quality and reliability. The brand recommends taking the non-GMO, gluten-free, soy-free, vegan capsules without food.

Best Zinc: Thorne Research Zinc Picolinate 15mg

Thorne Zinc Picolinate 15mg
Courtesy of Thorne.

Zinc is shown to support immune cells, and similar to vitamin C, it may also reduce the severity and duration of the common cold.

Thorne is a trusted brand with a commitment to high-quality products that are tested for quality, safety, and efficacy. The company prides itself on offering research-backed ingredients that are highly potent and easily absorbed. Thorne Research capsules contain 15 mg of zinc picolinate, a highly absorbable form of zinc. The capsules are free of gluten, GMOs, artificial preservatives, and all of the major allergens, so it’s accessible to a wide variety of people.

Best Vitamin D: Nordic Naturals Vitamin D3 1000 IU

Anecdotally, sunshine is always a great way to boost mood and immunity. In fact, exposure to sunshine boosts vitamin D production in the skin which may in turn support the immune system. Research published in 2010 shows that supplementation with vitamin D3 may be protective against the flu.

Each once-daily soft gel of Nordic Naturals Vitamin D3 provides 1000IU, or 125% of the recommended daily value. Nordic Natural's non-GMO product is third-party tested and NSF-Certified to ensure you're getting the highest quality vitamin possible that complies with strict manufacturing standards. Nordic Naturals recommends taking the supplement with food, as vitamin D is a fat-soluble vitamin, which is best absorbed with healthy sources of fat in the diet.

Best Elderberry: Gaia Herbs Black Elderberry Syrup

Known as Sambucus nigra, elderberry has been used throughout history to fight cold and flu symptoms. Research published in 2011 shows that elderberry could provide protection against the flu, so adding this supplement to your flu-season routine (or any time throughout the year) may be beneficial.

Gaia Herbs Black Elderberry Syrup is a great-tasting, plant-based syrup that is safe and effective for the entire family (age 1+). Each teaspoon serving contains the equivalent of 14.5 grams of fresh elderberries, as well as 147mg of acerola extract, an immunity-boosting fruit with very high vitamin C content.

The USDA Organic product is purity tested to ensure that it is free of pesticides, microbes and heavy metals. It's also vegan and free of corn, dairy, gluten, peanuts, shellfish, soy, tree nuts, and yeast.

Best Echinacea: Gaia Herbs Echinacea Supreme

Gaia Herbs Echinacea
Courtesy of Amazon.

Taking echinacea while you're feeling well is thought to reduce the chances of catching a cold. While more research is needed, there is some clinical evidence to support echinacea's immune-boosting properties.

Gaia Herbs' USDA Certified Organic Echinacea Supreme liquid extract blends two types of echinacea —echinacea purpurea and echinacea angustifolia— to create a highly potent supplement. Gaia recommends that adults take 40-60 drops at onset of symptoms in a small amount of water 4 to 6 times per day, in between meals. The purity-tested liquid is great for use at home or on-the-go and is free of dairy, gluten, and soy.

Best Turmeric: mykind Organics Extra Strength Turmeric Inflammatory Response

Traditionally celebrated for its anti-inflammatory effects, turmeric can also bolster the immune system.

Mykind Organics Extra Strength Turmeric Inflammatory Response provides a powerful 100mg of curcuminoids in each once-daily tablet. The USDA Organic, Certified-Vegan, and NSF-Certified Gluten-free supplement combines black pepper and ginger with turmeric to create a highly effective anti-inflammatory and immune booster.

Best Probiotic: Renew Life Ultimate Flora Probiotic

Probiotics are generally associated with gut health, however, the beneficial bacteria play a huge role in immune function. In addition to easing tummy troubles and improving digestion, probiotics help to regulate immune response, specifically maintaining a balance between innate and adaptive immune responses. They may block the growth of harmful bacteria, boost immune cells, and support natural antibodies.

Renew Life's Ultimate Flora Probiotic contains twelve strains of probiotics and 30 billion live cultures in each once-daily capsule. The vegetarian capsules are allergy-friendly, as they are free of gluten, soy, and dairy. Refrigeration is recommended, but not required, so you can take the bottle with you on-the-go.

What to Look for in an Immune-Boosting Supplement

Form

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

Type

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.

Dosage

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.

What Experts Say

"Our immune system is bolstered or suppressed by various lifestyle factors including nutrition, hydration, sleep, and stress. It’s important to look at the whole picture before turning to supplementation. That said, I recommend supplementation if someone's diet is missing a key nutrient, there is a known deficiency, during certain seasons (i.e. cold season), or when traveling." —Alanna Cabrero, RDN and founder of Alanna Cabrero Nutrition 

Why Trust Verywell Fit

A personal note on my recommendations written above. As a dietitian, I am careful to recommend supplements. I spent time reviewing the most current clinical research on specific herb and vitamin supplements that may support the immune system. I looked at multiple brands and products and consulted with trusted peers in dietetics. I believe the supplements in the round-up are made by trusted brands that are devoted to product purity and are composed of high-quality ingredients.

Personally, in addition to focusing on lifestyle factors, I take vitamin C, probiotics, and elderberry to boost my immune system. — Eliza Savage, MS, RD, CDN

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Article 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. Hemilä H. Vitamin C and Infections. Nutrients. 2017;9(4) doi:10.3390/nu9040339

  2. National Institutes of Health Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals. Updated February 27, 2020.

  3. National Institutes of Health Office of Dietary Supplements. Zinc Fact Sheet for Health Professionals. Updated March 6, 2020.

  4. Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am J Clin Nutr. 2010;91(5):1255-60. doi:10.3945/ajcn.2009.29094

  5. Krawitz C, Mraheil MA, Stein M, et al. Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses. BMC Complement Altern Med. 2011;11:16. doi:10.1186/1472-6882-11-16

  6. National Institutes of Health National Center for Complementary and Integrative Health. Echinacea. Updated September 2016.

  7. Yan F, Polk DB. Probiotics and immune healthCurr Opin Gastroenterol. 2011;27(6):496–501. doi:10.1097/MOG.0b013e32834baa4d