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Just like a firefighter, your immune's system first line of defense is import to the body's function.

Immune Support Supplements: What to Look for and How to Choose

Reviewed by: Caitlyn Edwards, PhD, RD, Senior Research Scientist, Research
5 MIN READ — 15 Citations — 05/29/2026

With so many immune supplements available, how do you know which is best? We break down key nutrients and what makes the most effective supplements.

Key Takeaways

  • 01.

    While nutrients like vitamin D, vitamin C, and zinc can support immune function, long-term immune health can be impacted by consistent, foundational nutrition.

  • 02.

    The effectiveness of immune supplements depends on the specific ingredient, dose, and bioavailable form, making quality and third-party testing important considerations.

  • 03.

    A balanced diet rich in whole foods and pre- and probiotics, along with healthy lifestyle habits, helps maintain a resilient and balanced immune system.

From powders and liquids to lozenges and gummies, there’s no shortage of immune system support supplements available. Understanding which nutrients and forms deliver real immune support requires looking beyond the label. While no single supplement can replace a healthy lifestyle, some single-ingredient supplements have been shown to support immune function. A foundational nutrition approach can help fill common nutrient gaps to support ongoing immune function. In this guide, we explore the top immune supplement options, how best to take them, and what to look for when assessing supplements.

What are immune support supplements?

The immune system is a complex network of cells, tissues, and organs that work together to support the body’s natural defense processes and overall wellness. To function properly, the body relies on a range of macro- and micronutrients that help support normal cellular activity and communication. A well-functioning immune system helps maintain balance and supports the body’s ability to respond to everyday physical and environmental stressors.

A well-rounded diet of whole foods, as well as regular exercise, adequate sleep, and managed stress levels, all contribute to maintaining immune balance. A balanced diet comes first. That said, many generally healthy people fall short of recommended nutrient intake levels.1 Supplements can help fill those common nutrient gaps—but they’re never a substitute for whole foods.

Immune support supplements usually target key vitamins, minerals, botanicals, or probiotics that have been studied for their roles in the immune system.

Benefits of immune support supplements

Different vitamins, minerals, and bioactive compounds support different aspects of the immune system. Key supplement ingredients include:

Vitamins and minerals

Vitamin D
Vitamin D supports normal immune function and plays a role in immune system signaling. Research suggests many Americans do not meet recommended vitamin D intake levels through diet and lifestyle alone.2 Sunlight is a primary source of vitamin D, which can make supplementation a helpful option during periods with reduced sun exposure, such as the winter months.3

Vitamin C
As a key antioxidant, vitamin C supports normal immune cell function and helps protect cells from oxidative stress. Vitamin C also plays a role in supporting immune system activity and cellular signaling. Research suggests many Americans do not meet recommended vitamin C intake levels.

Zinc
Zinc supports normal immune cell development and function and plays an important role in cellular signaling and antioxidant activity. Because the body does not naturally store zinc, consistent dietary intake is important for maintaining overall wellness and immune health.4

Botanicals

Elderberry
Elderberries are rich in antioxidants and contain naturally occurring phytonutrients that help support overall wellness. Elderberry has also been studied for its role in supporting normal immune system function and maintaining immune system balance. Some studies suggest elderberry may support respiratory wellness and overall immune function.5,6

Echinacea
Echinacea has been studied for its role in supporting normal immune system function and immune cell activity.7

Probiotics and their role in immune health

The GI tract is one of the immune system’s key command centers, where the body’s defenses are trained and managed. Driving this activity is the gut microbiome, a community of trillions of microbes that educate the immune system and help maintain balance. Probiotic supplements introduce live bacteria into the gut to enrich its diversity. However, not all probiotic strains offer immune support. When purchasing probiotics, look for strains such as Lactobacillus rhamnosus GG, Lactobacillus acidophilus NCFM, and Bifidobacterium lactis HN019, which have been studied for their immune benefits.8,9,10

In combination with a diet rich in prebiotic dietary fiber and other healthy lifestyle habits, probiotics can contribute to a thriving, balanced microbiome.

How to choose the right immune supplement

Beyond choosing which nutrients you want to supplement, consider the brand’s commitment to quality.

Bioavailability

Vitamins come in different chemical forms, some of which your body can absorb better than others. A quality supplement should use well-absorbed forms supported by research. For example, zinc picolinate and citrate are both highly absorbable and gentler on the stomach than some other forms.11,12 Zinc oxide is common and inexpensive, but some individuals absorb very little of it.13 Folate (B9) and vitamin E absorbability also vary depending on their form.14,15

Third-party certification

When assessing supplements, look for independent verification seals confirming the quality of the ingredients. NSF International’s Certified for Sport® program is one of the most rigorous and verifies that the ingredients match what is on the label and don’t contain any banned substances.

The Foundational Nutrition approach

Rather than taking many individual supplements, tracking intake, and assessing ingredients, many people choose an easy Foundational Nutrition supplement.

AG1 provides over 75 key vitamins, minerals, probiotics, and other bioactive compounds that help cover common nutrient gaps in a convenient, once-daily drink. It has also been designed to enhance bioavailability and uses only quality ingredients. Explore AG1 today.

References:

  1. Gombart AF, Pierre A, Maggini S. Inadequacy of immune health nutrients: intakes in US adults, the 2005-2016 NHANES. Nutrients. 2020;12(6):1735. doi:10.3390/nu12061735
  2. Gombart AF, Pierre A, Maggini S. Inadequacy of immune health nutrients: intakes in US adults, the 2005-2016 NHANES. Nutrients. 2020;12(6):1735. doi:10.3390/nu12061735
  3. Engelsen O. The relationship between ultraviolet radiation exposure and vitamin D status. Nutrients. 2010;2(5):482-495. doi:10.3390/nu2050482
  4. Hemilä H. Zinc lozenges and the common…: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. JRSM Open. 2017;8(5):2054270417694291. doi:10.1177/2054270417694291
  5. Wieland LS, Piechotta V, Feinberg T, et al. Elderberry…: a systematic review. BMC Complement Med Ther. 2021;21(1):112. doi:10.1186/s12906-021-03283-5
  6. Torabian G, Valtchev P, Adil Q, Dehghani F. … activity of elderberry (Sambucus nigra). J Funct Foods. 2019;54:353-360. doi:10.1016/j.jff.2019.01.031
  7. Wintergerst ES, Maggini S, Hornig DH. Contribution of selected vitamins and trace elements to immune function. Ann Nutr Metab. 2007;51(4):301-323. doi:10.1159/000107673
  8. Ashraf R, Shah NP. Immune system stimulation by probiotic microorganisms. Crit Rev Food Sci Nutr. 2014;54(7):938-956. doi:10.1080/10408398.2011.619671
  9. Kim Y, Mylonakis E. Caenorhabditis elegans immune conditioning with the probiotic bacterium Lactobacillus acidophilus strain NCFM enhances gram-positive immune responses. Infect Immun. 2012;80(7):2500-2508. doi:10.1128/IAI.06350-11
  10. Miller LE, Lehtoranta L, Lehtinen MJ. The effect of Bifidobacterium animalis ssp. lactis HN019 on cellular immune function in healthy elderly subjects: systematic review and meta-analysis. Nutrients. 2017;9(3):191. doi:10.3390/nu9030191
  11. Stiles LI, Ferrao K, Mehta KJ. Role of zinc in health and disease. Clin Exp Med. 2024;24(1):38. doi:10.1007/s10238-024-01302-6
  12. Barrie SA, Wright JV, Pizzorno JE, Kutter E, Barron PC. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions. 1987;21(1-2):223-228. doi:10.1007/BF01974946
  13. Cho WS, Kang BC, Lee JK, Jeong J, Che JH, Seok SH. Comparative absorption, distribution, and excretion of titanium dioxide and zinc oxide nanoparticles after repeated oral administration. Part Fibre Toxicol. 2013;10:9. doi:10.1186/1743-8977-10-9
  14. Skavinska O, Rossokha Z, Stefanyshyn V, Hrebeniuk O, Fishchuk L, Quadros EV, Gorovenko N. Comparative analysis of treatment with folate forms in clinical practice. Nutr Rev. Published online November 24, 2025. doi:10.1093/nutrit/nuaf216
  15. Jayawardena R, Sooriyaarachchi P, Chourdakis M, Jeewandara C, Ranasinghe P. Enhancing immunity in viral infections, with special emphasis on…: a review. Nutrients. 2020;12(12):3638. doi:10.3390/nu12123638