Given all we’ve collectively been through in 2020, it’s no surprise that the immune support category is on the rise: A July 2020 ResearchAndMarkets report predicts that the market will grow at 9% CAGR through 2025. When it comes to supplements that support immune health, there are plenty of options that go right to immune cells themselves, but that’s just one aspect of it. Supporting the immune system involves everything from digestive health supplements to stress supplements to sleep supplements and more.


The 101 on Immune

What is the immune system, and what does supports the immune system mean? With immune support needs on the rise, it’s more vital than ever to understand the immune system and how popular products work. A basic refresher: The immune system recognizes cells that have been infected or damaged, as well as infectious microbes such as viruses and bacteria, and either prevents them from getting in or mounts a response to destroy them (1). If the response falls short, people get sick; if the response goes overboard or activates without a threat, people can develop allergic reactions and autoimmune diseases.

The immune system splits into two general categories: innate and acquired, also known as adaptive. The innate immune system consists of preexisting mechanisms including the skin and mucosa; acquired immunity is targeted against a specific microorganism or antigen (2). Innate immunity works quickly, but the adaptive response can take days to weeks. For instance, a sneeze can immediately remove pathogens trapped in the mucosal lining of the nose, but it takes up to two weeks for the flu vaccine to begin working, because the acquired immune system has to recognize the viruses included in the vaccine and then form antibodies specific to those viruses.
Terms and Definitions
The immune system is made up of a vast number of tissues and cells. This rundown may be useful for your staff to review.

White blood cells, also known as leukocytes, are made in the bone marrow, and are found in the blood and lymph tissue (15). White blood cells are an overarching category, included in which are granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes (Natural Killer Cells, B cells, and T cells). As a whole, white blood cells help the body fight infections.

Granulocytes have, as the name would suggest, small granules, which contain proteins (16). Neutrophils, specifically, help the body fight bacterial infections. The number of granulocytes increases when there is a serious infection, but people with a lower number of granulocytes in general are more likely to develop infections more often.

Monocytes are made in the bone marrow and travel through tissues in the body, where the cells become macrophages or dendritic cells (17). Macrophages surround and kill microorganisms, ingest foreign material, remove dead cells, and boost immune responses. Dendritic cells work during the immune response, showing antigens on their surface to other cells in the immune system to boost the immune response.

Lymphocytes are made in the bone marrow. While they can be found in the blood, they mostly move through the lymphatic system, a group of tissues and organs including the spleen, tonsils, and lymph nodes, that protect the body from infection (18). Around 25% of lymphocytes remain in the bone marrow, where they become B cells, which recognize antigens and become plasma cells that produce antibodies to fight the antigens. The other 75% travel to the thymus and become T cells. There are three types of T cells: cytotoxic T cells, helper T cells, and regulatory T cells. Cytotoxic T cells—or killer T cells—destroy cells in the body that have been infected with an antigen, cancer cells, and foreign cells, such as those in transplanted organs. Helper T cells direct B cells and other T cells. Regulatory T cells suppress the immune system to keep its response in check, by preventing other white blood cells from fighting real or perceived antigens, including allergens and normal bacteria in the gut microbiome.

Natural Killer cells, while technically also lymphocytes, are actually part of the innate immune system, which respond rapidly to pathogens; they kill virally infected cells, and detect and control early signs of cancer (19). Unlike T cells, NK cells do not need to be primed by antigen presenting cells. They also secrete cytokines such as IFNy and TNFa, which act on other immune cells to enhance the immune response.

Immunoglobulins, produced by white blood cells, are more commonly known as antibodies (20). They recognize and bind to particular antigens and aid in their destruction. Five major classes have been identified in placental mammals—IgA, IgD, IgE, IgG, and IgM. Fun fact: Several of these immunoglobulins are found in chicken serum, and therefore in chicken broth—chicken soup for the soul, indeed.

9 to know

The claim supports the immune system is fairly broad, as is the range of products that can help. Here, we look at a few trending options—and we’ll be covering more in the months to come.

Astragalus. This herb contains natural flavonoids, trace minerals, and polyphenols, making it useful for general wellness. There is evidence that astragalus may increase the body’s production of white blood cells, and in animal research, the root has helped kill bacteria and viruses in mice with infections (3). Human research is limited, but some studies have found that it may help fight viral infections, including the common cold and infection of the liver.

Echinacea. Studies performed on echinacea have had mixed results; a 2014 review of several studies found that it could help prevent colds, and research has shown that it can increase the number of white blood cells (4). However, two studies funded by the National Center for Complementary and Integrative Health found no benefit (4). That said, it’s worth noting that the common cold is caused by any of more than 200 viruses that may react differently to the plant, and of course the strength and the quality of the plant can make a difference between studies. To this end, when stocking echinacea products, work with trusted, quality brands.

Elderberry. Elderberry has been shown in several small-scale studies to reduce duration of flu symptoms, and in one study was shown to decrease duration of illness following air travel (5). Artemis International reports that an animal study published in Science found that a specific microbe found in the gut may protect consumers of flavonoid-rich foods against the flu; Artemis noted that black elderberries are one of the foods richest in flavonoids (6). In rats, it was found to increase the number of white blood cells, thus supporting immune defense. The berries contain vitamin C as well as anthocyanins and phenolic acids, both of which are antioxidants, and flavonols including quercetin. When choosing supplements to stock, work with companies that ensure standardization of their berries, like INS Farms and Artemis. Inquire about testing—for instance, one study found that different tests can find wildly different anthocyanin content for the same sample—and only work with brands that can guarantee a quality product (5).

Fermentates. Yeast fermentates may support the immune system. One example: EpiCor, which was found in one randomized, double-blind, placebo-controlled clinical trial to significantly reduce incidence of cold and flu symptoms (7), and to reduce inflammation in rats and mice in two separate animal studies (8).

Palmitoylethanolamide (PEA). This compound is an anti-inflammatory agent. One review paper, which looked at 6 clinical trials in nearly 4,000 patients, concluded that PEA “should be reconsidered by clinicians as a new treatment modality for the flu and respiratory infections due to its documented efficacy and… its very benign side effect profile” (9). It inhibits the pro-inflammatory TNFa, among other regulatory actions, allowing it to support the immune response without inducing drug resistance. It can be found in eggs and milk, and is the star of CV Sciences’ CV Defense Daily Immune Support.

Vitamin A. Known best for its vision support properties, the vitamin also supports the integrity of epithelial and mucous tissue and helps regulate the differentiation, maturation, and function of macrophages and neutrophils, both part of the innate immune system (10). Infections may result in a decrease in systemic vitamin A, and the vitamin can also be lost through urine during infection. Those looking to maintain levels can find it in carrots, broccoli, liver, fish, and dairy products—and, of course, in many supplements, including a daily multi.

Vitamin C. Vitamin C works by supporting both the innate and the adaptive immune system, according to a 2017 paper published in Nutrients (11). It promotes antioxidant activity of the skin, thereby supporting the body’s first line of defense; it accumulates in phagocytic cells, and can therefore enhance microbial killing. The paper notes that its role in lymphocytes is less clear, but that it has been shown to help with the differentiation and proliferation of B- and T-cells. Not only does vitamin C deficiency impair the immune system, but an immune response requires more vitamin C intake than usual, so that the paper notes that while the baseline requirements for vitamin C are 100-200 mg/day, higher doses are necessary in times of increased demand—when sick, stressed, or when fighting off a disease.

Vitamin D. Vitamin D “plays a pivotal role in promoting innate immune response,” according to a 2018 paper. It enhances the production of antimicrobial agents, can regulate cytokine production, and can modulate the immune response (12). Mushrooms and oily fish are some of the best food sources, but fortified foods come into play here: milks, cereals, and yogurt can help your customers obtain this vitamin in their diet. Depending on where your store is located, this may be a good way to inspire your customers to head outside; sunlight will help raise the body’s levels of vitamin D, while making your customers feel better overall, and perhaps driving away some of those social isolation blues. In the supplement aisle, consider playing up vegetarian-friendly products like Bluebonnet’s Vitamin D3; as some of the best food sources for this vitamin are animal products, vegetarians will appreciate an easy source.

Zinc. Zinc is necessary for immune cell development and communication, and it plays a role in the inflammatory response (13). Studies have found it protective against respiratory tract infections, as well as helpful for those who are already sick with respiratory tract infections or the common cold (13). The National Institutes of Health note that the body has no zinc storage system, so daily zinc intake is required to maintain health (14). NIH points to oysters, red meat, crab, and lobster as the best dietary sources of zinc, and explains that while plant sources like beans and pumpkin seeds exist, compounds called phytates bind zinc and inhibit its absorption. Thus, plant sources aren’t as bioavailable as animal sources, although they still offer plenty. Those looking to supplement with zinc will want one that also contains copper, such as Trace Minerals’ Ionic Zinc; high levels of zinc can inhibit copper absorption, so adding extra is vital.


…and that’s just the beginning

Looking for more on the science behind these and other immune support basics, and a better grasp on this growing market? Head to to view the entire Taking Control of the Immunity & Wellness Market event on demand, and check out parts 2, 3, and 4 of this series. WF
  1. “Overview of the Immune System.” National Institute of Allergy and Infectious Diseases. Posted 12/30/2013. Accessed 12/1/2020.
  2. Beatriz Aristizábal and Angel González, “Innate Immune System.” In: JM Anaya et al., “Autoimmunity: From Bench to Bedside.” El Rosario University Press. 2013. Accessed 12/1/2020.
  3. Makayla Meixner, “Astragalus: An Ancient Root with Health Benefits,” Healthline. Posted 10/31/2018. Accessed 12/1/2020.
  4. “Echinacea for the Common Cold,” WebMD. Accessed 12/1/2020.
  5. Elise Mandl, “Elderberry: Benefits and Dangers.” Healthline. Posted 03/8/2018. Accessed 12/1/2020.
  6. “Flavonoids Show Benefits against Flu Infections Especially When A Specific Gut Bacterium Is Present.” Artemis International. Accessed 12/1/2020.
  7. Moyad, Mark A et al. “Immunogenic yeast-based fermentate for cold/flu-like symptoms in nonvaccinated individuals.” Journal of alternative and complementary medicine. 16(2). 213-8(2010).
  8. Evans, Malkanthi et al. “A dried yeast fermentate prevents and reduces inflammation in two separate experimental immune models.” Evidence-based complementary and alternative medicine. 2012 (2012).
  9. J. M. Keppel Hesselink et al. “Palmitoylethanolamide: A Natural Body-Own Anti-Inflammatory Agent, Effective and Safe against Influenza and Common Cold.” International Journal of Inflammation. 2013 (2013).
  10. Zhiyi Huang et al. “Role of Vitamin A in the Immune System.” Journal of Clinical Medicine. 7(9). 2018.
  11. Anitra C. Carr and Silvia Maggini, “Vitamin C and Immune Function,” Nutrients. 9(11); 1211. 2017. Accessed 12/01/2020.
  12. Giulia Bivona, Luisa Agnello, and Marcello Ciaccio, “The immunological implication of the new vitamin D metabolism,” Central European Journal of Immunology. 43(3); 331-334. 2018. Accessed 12/01/2020.
  13. Jillian Kubala, “The Fifteen Best Supplements to Boost Your Immune System Right Now.” Healthline. Posted 05/7/2020. Accessed 12/1/2020.
  14. “Zinc.” National Institutes of Health Office of Dietary Supplements. Updated 07/15/2020. Accessed 12/1/2020.
  15. “White Blood Cell.” National Cancer Institute. Accessed 12/1/2020.
  16. “Granulocyte.” MedlinePlus. Accessed 12/1/2020.
  17. “Monocyte.” National Cancer Institute. Accessed 12/1/2020.
  18. Susan York Morris, “Everything You Should Know About Lymphocytes,” Healthline. Updated 9/28/2018. Accessed 12/1/2020.
  19. “Natural Killer Cells.” British Society for Immunology. Accessed 12/1/2020.
  20. “Introduction to Immunoglobulins.” ThermoFisher Scientific. Accessed 12/1/2020.