{"id":147,"date":"2023-01-22T13:54:32","date_gmt":"2023-01-22T18:54:32","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/rebootyourresiliencywithselfcare\/?post_type=chapter&p=147"},"modified":"2023-11-01T18:56:19","modified_gmt":"2023-11-01T22:56:19","slug":"reboot-the-immune-system","status":"web-only","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/rebootyourresiliencywithselfcare\/chapter\/reboot-the-immune-system\/","title":{"raw":"Reboot the Immune System","rendered":"Reboot the Immune System"},"content":{"raw":"Is it really possible to boost our immune system? What if we make lifestyle choices like improving our diet or take certain vitamins or herbals? We\u2019ve discussed how incredibly complex the immune system is, and how in order for it to function well, it requires balance in all of its intricate systems. Stress reduction and healthy living strategies such as eating nutritiously, maintaining a healthy weight, exercising regularly, drinking alcohol in moderation, stopping smoking, and getting adequate sleep are all natural ways to keep our immune system healthy.\r\n\r\nAt the first signs of cold symptoms such as a sore throat or generalized achiness, many people reach for well known items such as Vitamin C, echinacea, and zinc lozenges. While it\u2019s important to follow a healthy diet rich in nutrients, even those whom we might think eats a clean diet may not be consuming a proper balance, or someone with a GI issue may not be absorbing the nutrients properly. \u00a0Demonstrating whether a substance actually enhances immunity is a very complicated matter, but there is much research that links many substances and their benefits for overall immunity.\r\n\r\nLet\u2019s discuss a few of the most common substances in deeper detail to get into the science behind how they work to bolster our immune system.\r\n\r\nZinc<\/strong>\r\n\r\nZinc is one of the most abundant minerals in our body, second only to iron. It is an essential trace element that is needed to support normal growth such as dividing cells, making proteins and DNA, as well as supporting healthy skin by healing wounds and assisting to keep our immune system strong.[footnote]Rabinovich, D., & Smadi, Y. (2022). Zinc. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK547698\/[\/footnote]\r\n\r\nZinc is called \u201cessential\u201d because we need to get enough of it daily through our diet as our body can\u2019t store it. The Recommended Dietary Allowance (RDA) for adults is 8 mg\/ day for women and 11 mg\/day for men.[footnote]Institute of Medicine. (2001). Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US). Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK222317\/[\/footnote] The Tolerable Upper Intake Level (UL) for adults is 40 mg\/day. While most North American diets provide the recommended dietary allowance via foods like red meat, poultry and seafood, some demographics may have subclinical zinc deficiency that they are not aware of. Individuals with digestive malabsorption disorders such as Ulcerative Colitis, Crohn\u2019s Disease and untreated or unknown Celiac Disease can have decreased zinc absorption.[footnote]Zuvarox, T.,& Belletieri, C. (2022). Malabsorption Syndromes. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK553106\/[\/footnote] Many alcoholics are fundamentally malnourished with micronutrient deficiencies as they tend to decrease their food intake or quality of food intake in lieu of alcohol. It should be noted that while legumes and whole grains are foods that contain zinc, the zinc is less bioavailable to the body, so vegetarians and vegans can be susceptible to zinc deficiency.[footnote]Harvard School of Public Health. The Nutrition Source. Zinc. Retrieved from: https:\/\/www.hsph.harvard.edu\/nutritionsource\/zinc\/[\/footnote]\r\n
Zinc has become a popular treatment for the common cold. \u00a0Many people turn to zinc lozenges or supplements when they start feeling under the weather. Some studies have found that zinc lozenges may reduce the duration of a cold by a day or two if taken within 24 hours of the onset of symptoms, as well as reduce the severity of symptoms.[footnote]Rao, G., & Rowland, K. (2011). PURLs: Zinc for the common cold--not if, but when. The Journal of family practice, 60(11), 669\u2013671. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3273967\/[\/footnote]<\/div>\r\nSo how does zinc actually work to bolster our immune system? Here's some info for you science geeks.\ud83d\ude09\r\n\r\nThe body needs zinc to develop and activate T-cells, and even mild zinc deficiency can weaken some white blood cell functions.[footnote]Prasad A. S. (2008). Zinc in human health: effect of zinc on immune cells. Molecular medicine (Cambridge, Mass.), 14(5-6), 353\u2013357. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC2277319\/[\/footnote] Zinc not only helps produce these substances that help in the immune response but also stops their production when they\u2019re no longer needed.[footnote]Wong, C. P., Rinaldi, N. A., & Ho, E. (2015). Zinc deficiency enhanced inflammatory response by increasing immune cell activation and inducing IL6 promoter demethylation. Molecular nutrition & food research, 59(5), 991\u2013999. Retrieved from: https:\/\/pubmed.ncbi.nlm.nih.gov\/25656040\/[\/footnote] In this way zinc acts with a feedback loop, or \"on-off\" switch in the immune system by slowing down the immune response and limiting the amount of inflammation once the initial response has been mounted. While we want a robust inflammatory response to defend us against an invading pathogen, too much inflammation attacks not only the pathogen but can also cause much more collateral damage. Zinc deficiency then, impairs not only the first responder functions, but also decreases the ability of the body to stop the inflammatory pathway once it has begun.[footnote]Ohio State University. (2013). Zinc helps against infection by tapping brakes in immune response. ScienceDaily. Retrieved from: www.sciencedaily.com\/releases\/2013\/02\/130207131344.htm[\/footnote]\r\n\r\nWhile recent research is showing that there are many benefits to zinc supplementation to boost our immune system, too much zinc can be detrimental, and supplementation should be carried out with caution. Reciprocally, an overabundance of zinc has been found to depress immune function, potentially reducing the number of T-cells with resultant decreased ability of the body to fight infections.[footnote]Wessels, I., Maywald, M., & Rink, L. (2017). Zinc as a Gatekeeper of Immune Function. Nutrients, 9(12), 1286. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC5748737\/[\/footnote] High zinc intake can also inhibit copper absorption, which in turn can alter iron function, resulting in anemia.[footnote]Wapnir, R.A., Balkman, C. (1991). Inhibition of copper absorption by zinc. Biological Trace Element Research 29(3): 193\u2013202.[\/footnote]\r\n\r\nVitamin D<\/strong>\r\n\r\nVitamin D is a fat-soluble vitamin that plays an enormous role in numerous processes in our body. One of its main roles is to help absorption of calcium to occur and also regulate our blood calcium and phosphate concentrations[footnote]Charoenngam, N., & Holick, M. F. (2020). Immunologic Effects of Vitamin D on Human Health and Disease. Nutrients, 12(7), 2097. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7400911\/[\/footnote] This is key for bone mineralization as well as growth and remodeling by [pb_glossary id=\"565\"]osteoblasts[\/pb_glossary] and [pb_glossary id=\"564\"]osteoclasts[\/pb_glossary]. Vitamin D is also involved in other things such as cell growth, neuromuscular function, and immune function.[footnote]Charoenngam, N., & Holick, M. F. (2020). Immunologic Effects of Vitamin D on Human Health and Disease. Nutrients, 12(7), 2097. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7400911\/[\/footnote]\r\n\r\n \r\n\r\n[caption id=\"attachment_686\" align=\"aligncenter\" width=\"1024\"]\"\"<\/a> Figure 10.1 Sundog[\/caption]\r\n\r\nVitamin D is often called \u201cthe sunshine vitamin\u201d because we produce it when we expose our skin to sunlight (UVB). We can make all of the vitamin D we need if exposure to sunlight is optimal and liver and kidney function are normal<\/span>.[footnote]Nair, R., & Maseeh, A. (2012). Vitamin D: The \"sunshine\" vitamin. Journal of pharmacology & pharmacotherapeutics, 3(2), 118\u2013126. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3356951\/[\/footnote] Because Vitamin D is \u201cactivated\u201d in our body by our kidneys and liver, if we have kidney or liver disease our activation will be impaired. Vitamin D is actually classified as a hormone because it\u2019s synthesized in our skin and has function elsewhere. We actually have Vitamin D receptors in our bones, small and large intestines, our brain, and our immune cells.[footnote]Bikle, D.D. (2021). Vitamin D: Production, Metabolism and Mechanisms of Action. In: Feingold, K.R., Anawalt, B., Boyce, A., et al., editors. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK278935\/[\/footnote]\r\n\r\nRegarding immunity, Vitamin D research has shown that B-cells and T-cells have Vitamin D receptors that use Vitamin D to make enzymes that help to fight infection in a variety of ways[footnote]Bikle, D.D. (2021). Vitamin D: Production, Metabolism and Mechanisms of Action. In: Feingold, K.R., Anawalt, B., Boyce, A., et al., editors. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK278935\/[\/footnote] [footnote]Kongsbak, M., Levring, T. B., Geisler, C., & von Essen, M. R. (2013). The vitamin d receptor and T cell function. Frontiers in immunology, 4, 148. Retrieved from: https:\/\/pubmed.ncbi.nlm.nih.gov\/23785369\/[\/footnote]\r\n\r\nTo achieve optimal Vitamin D levels with the sun alone, one must have full sunlight exposure with minimal clothing and no sunscreen during the middle of the day for an extended period of time.\u00a0Ultimately, many people can\u2019t achieve therapeutic Vitamin D levels with the sun alone because of medical issues such as with the kidneys and liver as discussed, but also due to geographical location, lifestyle choices, or seasonal changes.[footnote]Kennel, K. A., Drake, M. T., & Hurley, D. L. (2010). Vitamin D deficiency in adults: when to test and how to treat. Mayo Clinic proceedings, 85(8), 752\u2013758. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC2912737\/[\/footnote]\r\n
\r\n

Did You Know?<\/strong><\/p>\r\n\r\n<\/header>\r\n

More than 60% of people worldwide are Vitamin D deficient for a variety of reasons.[footnote]Kennel, K. A., Drake, M. T., & Hurley, D. L. (2010). Vitamin D deficiency in adults: when to test and how to treat. Mayo Clinic proceedings, 85(8), 752\u2013758. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC2912737\/[\/footnote]<\/div>\r\n<\/div>\r\nMelanin in the skin can reduce the effectiveness of sunlight producing Vitamin D, which is why people with darker skin have been documented to have lower Vitamin D levels, even if they live in temperate climates.[footnote]Bikle, D.D. (2021). Vitamin D: Production, Metabolism and Mechanisms of Action. In: Feingold, K.R., Anawalt, B., Boyce, A., et al., editors. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK278935\/[\/footnote] In the Northern Hemisphere between the months of October and April, the suns rays are not strong enough to synthesize Vitamin D on our skin. Deficiency of Vitamin D can occur when sunlight exposure is decreased due to these environmental factors, as well as cultural clothing customs concealing our body, or the inability of older adults or people with disabilities to get outdoors. In addition, as we get older, we cannot synthesize as much Vitamin D due to aging skin changes.[footnote]Kennel, K. A., Drake, M. T., & Hurley, D. L. (2010). Vitamin D deficiency in adults: when to test and how to treat. Mayo Clinic proceedings, 85(8), 752\u2013758. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC2912737\/[\/footnote] The fact that most people\u2019s Vitamin D levels are lowest in the winter suggests a possible link to the increased occurrence of infections during wintertime. Vitamin D is widely researched, and there are many studies that show low Vitamin D levels are associated with respiratory tract infections such as cold and flu[footnote]Greiller, C. L., & Martineau, A. R. (2015). Modulation of the immune response to respiratory viruses by vitamin D. Nutrients, 7(6), 4240\u20134270. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC4488782\/[\/footnote], inflammatory conditions such as allergies and asthma,[footnote]Murdaca, G., Gerosa, A., Paladin, F., Petrocchi, L., Banchero, S., & Gangemi, S. (2021). Vitamin D and Microbiota: Is There a Link with Allergies?. International journal of molecular sciences, 22(8), 4288. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC8074777\/[\/footnote] inflammatory bowel disease (IBD)[footnote]Battistini, C., Ballan, R., Herkenhoff, M. E., Saad, S. M. I., & Sun, J. (2020). Vitamin D Modulates Intestinal Microbiota in Inflammatory Bowel Diseases. International journal of molecular sciences, 22(1), 362. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7795229\/[\/footnote], chronic pain conditions[footnote]Straube, S., Derry, S., Straube, C., & Moore, R. A. (2015). Vitamin D for the treatment of chronic painful conditions in adults. The Cochrane database of systematic reviews, 2015(5), CD007771. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC6494161\/[\/footnote]and autoimmune disorders such as multiple sclerosis.[footnote]Jagannath, V. A., Filippini, G., Di Pietrantonj, C., Asokan, G. V., Robak, E. W., Whamond, L., & Robinson, S. A. (2018). Vitamin D for the management of multiple sclerosis. The Cochrane database of systematic reviews, 9(9), CD008422. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC6513642\/[\/footnote]\r\n\r\nThe most common form of Vitamin D in the diet and supplements is D3 (cholecalciferol). A wide \u201coptimal\u201d range for Vitamin D blood levels is reported (25-80 ng\/mL), and differences of opinion exist as to what deficiencies are defined as.[footnote]Kennel, K. A., Drake, M. T., & Hurley, D. L. (2010). Vitamin D deficiency in adults: when to test and how to treat. Mayo Clinic proceedings, 85(8), 752\u2013758. Retrieved from: https:\/\/doi.org\/10.4065\/mcp.2010.0138[\/footnote] In general, scientific literature and health experts assert that 50 ng\/ml is the optimal serum Vitamin D level we should all strive for to support our health and well-being.[footnote]Heaney R. P. (2008). Vitamin D in health and disease. Clinical journal of the American Society of Nephrology : CJASN, 3(5), 1535\u20131541. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC4571146\/[\/footnote]\r\n\r\nWhile the maximum safe dosage of Vitamin D remains disputed, North America\u2019s current tolerable upper intake level is 2000 IU (50 \u00b5g) per day in North America; however, some scientists recommend an increase to 5,000 IU per day.[footnote]Centres for Disease Control and Prevention. (2022). National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population 1999-2002. Vitamin D. Retrieved from: https:\/\/www.cdc.gov\/nutritionreport\/99-02\/pdf\/nr_ch2b.pdf[\/footnote] [footnote]Heaney R. P. (2008). Vitamin D in health and disease. Clinical journal of the American Society of Nephrology : CJASN, 3(5), 1535\u20131541. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC4571146\/[\/footnote] It actually takes 100 IU of Vitamin D to increase a normal-weight adult\u2019s serum D levels by about 10 ng\/ml, so to achieve optimal levels of 50 ng\/ml, a person would need 5000iu per day.[footnote]Heaney R. P. (2008). Vitamin D in health and disease. Clinical journal of the American Society of Nephrology : CJASN, 3(5), 1535\u20131541. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC4571146\/[\/footnote]\r\n\r\nNot many foods naturally contain Vitamin D. The flesh of fatty fish such as trout and salmon are among the best sources. Small amounts of Vitamin D can be found in beef liver, cheese, and egg yolks. As a comparison, a serving of trout provides 645iu while 1.5 ounces of cheddar cheese provides 17iu.[footnote]National Institutes of Health. (2022). Vitamin D. Retrieved from: https:\/\/ods.od.nih.gov\/factsheets\/VitaminD-HealthProfessional\/[\/footnote] In general, fortified milk has 100iu per cup, and it can also be found in some orange juices and ready-to-eat cereals.[footnote]Straube, S., Derry, S., Straube, C., & Moore, R. A. (2015). Vitamin D for the treatment of chronic painful conditions in adults. The Cochrane database of systematic reviews, 2015(5), CD007771. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC6494161\/[\/footnote] Achieving high levels through diet alone would be very difficult. Research in 2017 illustrated that daily Vitamin D supplementation could help prevent colds and flu, especially in those people who were deficient in Vitamin D.[footnote]Martineau, A.R., Jolliffe, D. A., Hooper, R. L., Greenberg, L., Aloia, J. F., Bergman, P. et al. (2017). Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ, 356. Retrieved from: https:\/\/www.bmj.com\/content\/356\/bmj.i6583[\/footnote] A different study focused on Vitamin D-deficient participants, found that Vitamin D supplementation can decrease viral respiratory infection by 70%.[footnote]Meltzer, D.O., Best, T.J., Zhang, H., Vokes, T., Arora, V., Solway, J. (2020). Association of Vitamin D Status and Other Clinical Characteristics With COVID-19 Test Results. JAMA Netw Open.<\/em> 2020;3(9):e2019722. Retrieved from: https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/fullarticle\/2770157[\/footnote] Since Vitamin D is a fat soluble vitamin, it gets stored in our body, so extreme supplementation must be used with caution..\r\n\r\nVitamin C<\/strong>\r\n\r\nIs Vitamin C your go-to when the sniffles come?\r\n\r\n \r\n\r\n[caption id=\"attachment_340\" align=\"aligncenter\" width=\"1024\"]\"\"<\/a> Figure 10.2 Linus Pauling[\/caption]\r\n\r\n\r\n\r\nVitamin C, or ascorbic acid, is an essential water-soluble vitamin, so it must be taken daily via food or supplements. Vitamin C is mostly found in fruits such as citrus fruits and strawberries, and vegetables such as red and green peppers, tomatoes, potatoes, broccoli, and other green leafy vegetables.[footnote]Hill, C., Kelly, E. (2022). 20 Foods That Are High in Vitamin C. Healthline. Retrieved from: https:\/\/www.healthline.com\/nutrition\/vitamin-c-foods[\/footnote] At-risk groups for Vitamin C deficiency include chronic alcohol and drug users, smokers, those with some gastrointestinal diseases and some cancers, and of course individuals with inadequate dietary intakes of fruits and vegetables.[footnote]Mayo Clinic. (2023). Vitamin C. Retrieved from: https:\/\/www.mayoclinic.org\/drugs-supplements-vitamin-c\/art-20363932[\/footnote]\r\n\r\nVitamin C is necessary for collagen formation for our bone matrix, teeth, cartilage, skin, and connective tissue.[footnote]Mayo Clinic. (2023). Vitamin C. Retrieved from: https:\/\/www.mayoclinic.org\/drugs-supplements-vitamin-c\/art-20363932[\/footnote]Thus, Vitamin C is integral to wound healing as it is vital for the growth and repair of body tissues. [footnote]Institute of Medicine. (2000). Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. 5, Vitamin C. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK225480\/[\/footnote]\r\n\r\n[caption id=\"attachment_339\" align=\"aligncenter\" width=\"1024\"]\"\"<\/a> Figure 10.3 Vitamin C[\/caption]\r\n\r\nVitamin C acts as a powerful [pb_glossary id=\"674\"]antioxidant[\/pb_glossary] with versatile anti-inflammatory properties.[footnote]G\u0119gotek, A., & Skrzydlewska, E. (2022). Antioxidative and Anti-Inflammatory Activity of Ascorbic Acid. Antioxidants (Basel, Switzerland), 11(10), 1993. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC9598715\/[\/footnote] Antioxidants protect our cells from harmful [pb_glossary id=\"675\"]free radicals[\/pb_glossary] that promote [pb_glossary id=\"676\"]oxidative stress[\/pb_glossary].[footnote]Pham-Huy, L. A., He, H., & Pham-Huy, C. (2008). Free radicals, antioxidants in disease and health. International journal of biomedical science : IJBS, 4(2), 89\u201396. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3614697\/[\/footnote] Oxidative stress has been associated with many chronic diseases, and research has illustrated that ingesting Vitamin C can increase blood antioxidant levels, helping the body fight inflammation.[footnote]Sasazuki, S., Hayashi, T., Nakachi, K., Sasaki, S., Tsubono, Y., Okubo, S., Hayashi, M., & Tsugane, S. (2008). Protective effect of vitamin C on oxidative stress: a randomized controlled trial. International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition, 78(3), 121\u2013128.[\/footnote] [footnote]Liguori, I., Russo, G., Curcio, F., Bulli, G., Aran, L., Della-Morte, D., Gargiulo, G., Testa, G., Cacciatore, F., Bonaduce, D., & Abete, P. (2018). Oxidative stress, aging, and diseases. Clinical interventions in aging, 13, 757\u2013772. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC5927356\/[\/footnote]One study did an analysis of 9 different studies, indicating that over a 10 year period, people who took 700mg of Vitamin C daily had a 25% lower risk of heart disease than those didn\u2019t take a supplement.[footnote]Knekt, P., Ritz, J., Pereira, M. A., O'Reilly, E. J., Augustsson, K., Fraser, G. E., Goldbourt, U., Heitmann, B. L., Hallmans, G., Liu, S., Pietinen, P., Spiegelman, D., Stevens, J., Virtamo, J., Willett, W. C., Rimm, E. B., & Ascherio, A. (2004). Antioxidant vitamins and coronary heart disease risk: a pooled analysis of 9 cohorts. The American journal of clinical nutrition, 80(6), 1508\u20131520.[\/footnote] Another research analysis showed that Vitamin C supplementation lowers low-density lipoproteins (LDL) \u2013 the \u201cbad\u201d cholesterol \u2013 and triglycerides.[footnote]McRae M. P. (2008). Vitamin C supplementation lowers serum low-density lipoprotein cholesterol and triglycerides: a meta-analysis of 13 randomized controlled trials. Journal of chiropractic medicine, 7(2), 48\u201358. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC2682928\/[\/footnote]\r\n\r\nVitamin C is well known for its integral role in supporting a strong immune system.[footnote]Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC5707683\/[\/footnote] Vitamin C enhances epithelial barrier functions, thereby strengthening our first line of defense against invading pathogens.[footnote]Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC5707683\/[\/footnote] Vitamin C also appears to potentiate many important aspects of neutrophil function.[footnote]Bozonet, S. M., & Carr, A. C. (2019). The Role of Physiological Vitamin C Concentrations on Key Functions of Neutrophils Isolated from Healthy Individuals. Nutrients, 11(6), 1363. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC6627200\/[\/footnote] Some research has shown that Vitamin C supplements might even shorten how long a person has the common cold in addition to decreasing the severity of symptoms.[footnote]Institute of Medicine (2000). Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. 5, Vitamin C. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK225480\/[\/footnote] [footnote]Hemil\u00e4 H. (2017). Vitamin C and Infections. Nutrients, 9(4), 339. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC5409678\/[\/footnote]\r\n\r\nTo provide antioxidant protection, 90 mg\/day for adult men and 75 mg\/day for adult women is recommended for those in optimal health<\/span>.[footnote]Government of Canada. (2022). Dietary Reference Intakes. Retrieved from: https:\/\/www.canada.ca\/en\/health-canada\/services\/food-nutrition\/healthy-eating\/dietary-reference-intakes\/tables\/reference-values-vitamins-dietary-reference-intakes-tables-2005.html[\/footnote] Others are recommended to increase their daily intake.\r\n
\r\n

Did You Know?<\/strong><\/p>\r\n\r\n<\/header>\r\n

Smoking increases oxidative stress and metabolic turnover of Vitamin C.<\/div>\r\n<\/div>\r\nThe Tolerable Upper Intake Level (UL) for adults is set at 2 g\/day, as gastrointestinal disturbances such as diarrhea can occur for some people above these levels.[footnote]Institute of Medicine (2000). Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. 5, Vitamin C. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK225480\/[\/footnote]\r\n\r\nIt is important to note that while Vitamin C deficiency results in impaired immunity and higher susceptibility to infections, when someone has an active infection, inflammation, or wounds, Vitamin C levels are significantly impacted due to increased metabolic requirements for healing. \u00a0Thus a person who has increased metabolic demand would need higher doses of Vitamin C overall.[footnote]Figueroa-M\u00e9ndez, R., & Rivas-Arancibia, S. (2015). Vitamin C in Health and Disease: Its Role in the Metabolism of Cells and Redox State in the Brain. Frontiers in physiology, 6, 397. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC4688356\/[\/footnote]\r\n\r\nVitamin A<\/strong>\r\n\r\nThe effects of Vitamin A on our bodies aren\u2019t generally well known by many people. Some people know that it\u2019s imperative for your vision, or that if you use it topically (Retin-A) it can help acne and wrinkles, but did you know that it is crucial for the immune system? Vitamin A plays a critical role in enhancing immune function and helping the antibody response.[footnote]Rumore M. M. (1993). Vitamin A as an immunomodulating agent. Clinical pharmacy<\/em>,\u00a012<\/em>(7), 506\u2013514.[\/footnote] \u00a0Vitamin A is also known as an anti-inflammatory vitamin, promoting cell growth and differentiation, and protecting epithelium and mucus integrity in the body.[footnote]Reifen R. (2002). Vitamin A as an anti-inflammatory agent.\u00a0The Proceedings of the Nutrition Society<\/em>,\u00a061<\/em>(3), 397\u2013400. Retrieved from: https:\/\/www.researchgate.net\/publication\/11159128_Vitamin_A_as_an_anti-inflammatory_agent[\/footnote] We know that the gut is the foundation of our immune system, so Vitamin A plays a huge part in maintaining its integrity and mucosal defenses as well as keeping inflammation in check.\r\n\r\nVitamin A is a fat-soluble vitamin, thus the body stores excess amounts, mostly in the liver. This means that excess Vitamin A supplementation can have significant toxic ramifications, most notably for the liver. Vitamin A deficiency is rarely seen in developed countries, but is common in developing countries.[footnote]World Health Organization. (2022). Vitamin A Deficiency. Retrieved from: https:\/\/www.who.int\/data\/nutrition\/nlis\/info\/vitamin-a-deficiency[\/footnote] Vitamin A is found in many foods such as eggs, dairy products, and organ meats such as liver. Other sources are foods rich in beta-carotene (provitamin A), the nutrient that is converted to Vitamin A in our bodies, such as green leafy vegetables and orange and yellow vegetables and fruits.\r\n\r\nHerbals<\/strong>\r\n\r\nThere are two herbals worth mentioning due to their significant antiviral and antibacterial properties that are well documented in science.\r\n\r\nBlack elderberry<\/strong> (sambucus nigra), is one of the most commonly used medicinal plants in the world, and traditionally, Indigenous people used it to treat colds, fever and rheumatism.[footnote]European Medicines Agency. (2014). Assessment report on Sambucus nigra L., fructus. Committee on Herbal Medicinal Products. Retrieved from: https:\/\/www.ema.europa.eu\/en\/documents\/herbal-report\/final-assessment-report-sambucus-nigra-l-fructus_en.pdf[\/footnote]\u00a0 Elderberry has demonstrated potent antibacterial and antiviral potential against bacterial upper respiratory infections as well as the influenza virus.[footnote]Krawitz, C., Mraheil, M. A., Stein, M., Imirzalioglu, C., Domann, E., Pleschka, S., & Hain, T. (2011). Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses. BMC complementary and alternative medicine, 11, 16. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3056848\/[\/footnote] [footnote]Tiralongo, E., Wee, S. S., & Lea, R. A. (2016). Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial. Nutrients, 8(4), 182. Retrieved from: https:\/\/pubmed.ncbi.nlm.nih.gov\/27023596\/[\/footnote] [footnote]Hawkins, J., Baker, C., Cherry, L., & Dunne, E. (2019). Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: A meta-analysis of randomized, controlled clinical trials. Complementary therapies in medicine, 42, 361\u2013365. Retrieved from: https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S0965229918310240?via=ihub[\/footnote]\r\n\r\n[caption id=\"attachment_683\" align=\"aligncenter\" width=\"1024\"]\"\"<\/a> Figure 10.4 Elderberry[\/caption]\r\n\r\nEchinacea<\/strong>, mainly the E. purpurea species, has been used for centuries to treat respiratory tract infections and inflammatory conditions.[footnote]Catanzaro, M., Corsini, E., Rosini, M., Racchi, M., & Lanni, C. (2018). Immunomodulators Inspired by Nature: A Review on Curcumin and Echinacea. Molecules (Basel, Switzerland), 23(11), 2778. Retrieved from: https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC6278270\/[\/footnote] Echinacea has been shown in research to reduce the duration and severity of cold symptoms.[footnote]Rondanelli M., Miccono A., Lamburghini S., Avanzato I., Riva A., Allegrini P., Faliva M.A., Peroni G., Nichetti M., Perna S. (2018). Self-care for common colds: The pivotal role of vitamin D, vitamin C, zinc and Echinacea in three main immune interactive clusters (physical barriers, innate and adaptive immunity) involved during an episode of common colds\u2014Practical advice on dosages and on the time to take these nutrients\/botanicals in order to prevent or treat common colds. Evid. Based Complement. Alternat. Med.[\/footnote] Research has also illustrated the anti-inflammatory, anti-viral and anti-bacterial effects of echinacea.[footnote]Percival S.S. (2000). Use of echinacea in medicine. Biochem. Pharmacol. 2000;60:155\u2013158.[\/footnote]\r\n\r\n[caption id=\"attachment_684\" align=\"aligncenter\" width=\"1024\"]\"\"<\/a> Figure 10.5 Echinacea[\/caption]\r\n\r\nSo there you have it! You've learned a lot about your immune system, it's connection to stress, and your ability to bolster it through healthy living and natural means. Take this knowledge to heart, and tie it in with the information to follow. Your body will thank you!","rendered":"

Is it really possible to boost our immune system? What if we make lifestyle choices like improving our diet or take certain vitamins or herbals? We\u2019ve discussed how incredibly complex the immune system is, and how in order for it to function well, it requires balance in all of its intricate systems. Stress reduction and healthy living strategies such as eating nutritiously, maintaining a healthy weight, exercising regularly, drinking alcohol in moderation, stopping smoking, and getting adequate sleep are all natural ways to keep our immune system healthy.<\/p>\n

At the first signs of cold symptoms such as a sore throat or generalized achiness, many people reach for well known items such as Vitamin C, echinacea, and zinc lozenges. While it\u2019s important to follow a healthy diet rich in nutrients, even those whom we might think eats a clean diet may not be consuming a proper balance, or someone with a GI issue may not be absorbing the nutrients properly. \u00a0Demonstrating whether a substance actually enhances immunity is a very complicated matter, but there is much research that links many substances and their benefits for overall immunity.<\/p>\n

Let\u2019s discuss a few of the most common substances in deeper detail to get into the science behind how they work to bolster our immune system.<\/p>\n

Zinc<\/strong><\/p>\n

Zinc is one of the most abundant minerals in our body, second only to iron. It is an essential trace element that is needed to support normal growth such as dividing cells, making proteins and DNA, as well as supporting healthy skin by healing wounds and assisting to keep our immune system strong.[1]<\/sup><\/a><\/p>\n

Zinc is called \u201cessential\u201d because we need to get enough of it daily through our diet as our body can\u2019t store it. The Recommended Dietary Allowance (RDA) for adults is 8 mg\/ day for women and 11 mg\/day for men.[2]<\/sup><\/a> The Tolerable Upper Intake Level (UL) for adults is 40 mg\/day. While most North American diets provide the recommended dietary allowance via foods like red meat, poultry and seafood, some demographics may have subclinical zinc deficiency that they are not aware of. Individuals with digestive malabsorption disorders such as Ulcerative Colitis, Crohn\u2019s Disease and untreated or unknown Celiac Disease can have decreased zinc absorption.[3]<\/sup><\/a> Many alcoholics are fundamentally malnourished with micronutrient deficiencies as they tend to decrease their food intake or quality of food intake in lieu of alcohol. It should be noted that while legumes and whole grains are foods that contain zinc, the zinc is less bioavailable to the body, so vegetarians and vegans can be susceptible to zinc deficiency.[4]<\/sup><\/a><\/p>\n

Zinc has become a popular treatment for the common cold. \u00a0Many people turn to zinc lozenges or supplements when they start feeling under the weather. Some studies have found that zinc lozenges may reduce the duration of a cold by a day or two if taken within 24 hours of the onset of symptoms, as well as reduce the severity of symptoms.[5]<\/sup><\/a><\/div>\n

So how does zinc actually work to bolster our immune system? Here’s some info for you science geeks.\ud83d\ude09<\/p>\n

The body needs zinc to develop and activate T-cells, and even mild zinc deficiency can weaken some white blood cell functions.[6]<\/sup><\/a> Zinc not only helps produce these substances that help in the immune response but also stops their production when they\u2019re no longer needed.[7]<\/sup><\/a> In this way zinc acts with a feedback loop, or “on-off” switch in the immune system by slowing down the immune response and limiting the amount of inflammation once the initial response has been mounted. While we want a robust inflammatory response to defend us against an invading pathogen, too much inflammation attacks not only the pathogen but can also cause much more collateral damage. Zinc deficiency then, impairs not only the first responder functions, but also decreases the ability of the body to stop the inflammatory pathway once it has begun.[8]<\/sup><\/a><\/p>\n

While recent research is showing that there are many benefits to zinc supplementation to boost our immune system, too much zinc can be detrimental, and supplementation should be carried out with caution. Reciprocally, an overabundance of zinc has been found to depress immune function, potentially reducing the number of T-cells with resultant decreased ability of the body to fight infections.[9]<\/sup><\/a> High zinc intake can also inhibit copper absorption, which in turn can alter iron function, resulting in anemia.[10]<\/sup><\/a><\/p>\n

Vitamin D<\/strong><\/p>\n

Vitamin D is a fat-soluble vitamin that plays an enormous role in numerous processes in our body. One of its main roles is to help absorption of calcium to occur and also regulate our blood calcium and phosphate concentrations[11]<\/sup><\/a> This is key for bone mineralization as well as growth and remodeling by osteoblasts<\/a> and osteoclasts<\/a>. Vitamin D is also involved in other things such as cell growth, neuromuscular function, and immune function.[12]<\/sup><\/a><\/p>\n

 <\/p>\n

\"\"<\/a>
Figure 10.1 Sundog<\/figcaption><\/figure>\n

Vitamin D is often called \u201cthe sunshine vitamin\u201d because we produce it when we expose our skin to sunlight (UVB). We can make all of the vitamin D we need if exposure to sunlight is optimal and liver and kidney function are normal<\/span>.[13]<\/sup><\/a> Because Vitamin D is \u201cactivated\u201d in our body by our kidneys and liver, if we have kidney or liver disease our activation will be impaired. Vitamin D is actually classified as a hormone because it\u2019s synthesized in our skin and has function elsewhere. We actually have Vitamin D receptors in our bones, small and large intestines, our brain, and our immune cells.[14]<\/sup><\/a><\/p>\n

Regarding immunity, Vitamin D research has shown that B-cells and T-cells have Vitamin D receptors that use Vitamin D to make enzymes that help to fight infection in a variety of ways[15]<\/sup><\/a> [16]<\/sup><\/a><\/p>\n

To achieve optimal Vitamin D levels with the sun alone, one must have full sunlight exposure with minimal clothing and no sunscreen during the middle of the day for an extended period of time.\u00a0Ultimately, many people can\u2019t achieve therapeutic Vitamin D levels with the sun alone because of medical issues such as with the kidneys and liver as discussed, but also due to geographical location, lifestyle choices, or seasonal changes.[17]<\/sup><\/a><\/p>\n

\n
\n

Did You Know?<\/strong><\/p>\n<\/header>\n

More than 60% of people worldwide are Vitamin D deficient for a variety of reasons.[18]<\/sup><\/a><\/div>\n<\/div>\n

Melanin in the skin can reduce the effectiveness of sunlight producing Vitamin D, which is why people with darker skin have been documented to have lower Vitamin D levels, even if they live in temperate climates.[19]<\/sup><\/a> In the Northern Hemisphere between the months of October and April, the suns rays are not strong enough to synthesize Vitamin D on our skin. Deficiency of Vitamin D can occur when sunlight exposure is decreased due to these environmental factors, as well as cultural clothing customs concealing our body, or the inability of older adults or people with disabilities to get outdoors. In addition, as we get older, we cannot synthesize as much Vitamin D due to aging skin changes.[20]<\/sup><\/a> The fact that most people\u2019s Vitamin D levels are lowest in the winter suggests a possible link to the increased occurrence of infections during wintertime. Vitamin D is widely researched, and there are many studies that show low Vitamin D levels are associated with respiratory tract infections such as cold and flu[21]<\/sup><\/a>, inflammatory conditions such as allergies and asthma,[22]<\/sup><\/a> inflammatory bowel disease (IBD)[23]<\/sup><\/a>, chronic pain conditions[24]<\/sup><\/a>and autoimmune disorders such as multiple sclerosis.[25]<\/sup><\/a><\/p>\n

The most common form of Vitamin D in the diet and supplements is D3 (cholecalciferol). A wide \u201coptimal\u201d range for Vitamin D blood levels is reported (25-80 ng\/mL), and differences of opinion exist as to what deficiencies are defined as.[26]<\/sup><\/a> In general, scientific literature and health experts assert that 50 ng\/ml is the optimal serum Vitamin D level we should all strive for to support our health and well-being.[27]<\/sup><\/a><\/p>\n

While the maximum safe dosage of Vitamin D remains disputed, North America\u2019s current tolerable upper intake level is 2000 IU (50 \u00b5g) per day in North America; however, some scientists recommend an increase to 5,000 IU per day.[28]<\/sup><\/a> [29]<\/sup><\/a> It actually takes 100 IU of Vitamin D to increase a normal-weight adult\u2019s serum D levels by about 10 ng\/ml, so to achieve optimal levels of 50 ng\/ml, a person would need 5000iu per day.[30]<\/sup><\/a><\/p>\n

Not many foods naturally contain Vitamin D. The flesh of fatty fish such as trout and salmon are among the best sources. Small amounts of Vitamin D can be found in beef liver, cheese, and egg yolks. As a comparison, a serving of trout provides 645iu while 1.5 ounces of cheddar cheese provides 17iu.[31]<\/sup><\/a> In general, fortified milk has 100iu per cup, and it can also be found in some orange juices and ready-to-eat cereals.[32]<\/sup><\/a> Achieving high levels through diet alone would be very difficult. Research in 2017 illustrated that daily Vitamin D supplementation could help prevent colds and flu, especially in those people who were deficient in Vitamin D.[33]<\/sup><\/a> A different study focused on Vitamin D-deficient participants, found that Vitamin D supplementation can decrease viral respiratory infection by 70%.[34]<\/sup><\/a> Since Vitamin D is a fat soluble vitamin, it gets stored in our body, so extreme supplementation must be used with caution..<\/p>\n

Vitamin C<\/strong><\/p>\n

Is Vitamin C your go-to when the sniffles come?<\/p>\n

 <\/p>\n

\"\"<\/a>
Figure 10.2 Linus Pauling<\/figcaption><\/figure>\n

<\/p>\n

Vitamin C, or ascorbic acid, is an essential water-soluble vitamin, so it must be taken daily via food or supplements. Vitamin C is mostly found in fruits such as citrus fruits and strawberries, and vegetables such as red and green peppers, tomatoes, potatoes, broccoli, and other green leafy vegetables.[35]<\/sup><\/a> At-risk groups for Vitamin C deficiency include chronic alcohol and drug users, smokers, those with some gastrointestinal diseases and some cancers, and of course individuals with inadequate dietary intakes of fruits and vegetables.[36]<\/sup><\/a><\/p>\n

Vitamin C is necessary for collagen formation for our bone matrix, teeth, cartilage, skin, and connective tissue.[37]<\/sup><\/a>Thus, Vitamin C is integral to wound healing as it is vital for the growth and repair of body tissues. [38]<\/sup><\/a><\/p>\n

\"\"<\/a>
Figure 10.3 Vitamin C<\/figcaption><\/figure>\n

Vitamin C acts as a powerful antioxidant<\/a> with versatile anti-inflammatory properties.[39]<\/sup><\/a> Antioxidants protect our cells from harmful free radicals<\/a> that promote oxidative stress<\/a>.[40]<\/sup><\/a> Oxidative stress has been associated with many chronic diseases, and research has illustrated that ingesting Vitamin C can increase blood antioxidant levels, helping the body fight inflammation.[41]<\/sup><\/a> [42]<\/sup><\/a>One study did an analysis of 9 different studies, indicating that over a 10 year period, people who took 700mg of Vitamin C daily had a 25% lower risk of heart disease than those didn\u2019t take a supplement.[43]<\/sup><\/a> Another research analysis showed that Vitamin C supplementation lowers low-density lipoproteins (LDL) \u2013 the \u201cbad\u201d cholesterol \u2013 and triglycerides.[44]<\/sup><\/a><\/p>\n

Vitamin C is well known for its integral role in supporting a strong immune system.[45]<\/sup><\/a> Vitamin C enhances epithelial barrier functions, thereby strengthening our first line of defense against invading pathogens.[46]<\/sup><\/a> Vitamin C also appears to potentiate many important aspects of neutrophil function.[47]<\/sup><\/a> Some research has shown that Vitamin C supplements might even shorten how long a person has the common cold in addition to decreasing the severity of symptoms.[48]<\/sup><\/a> [49]<\/sup><\/a><\/p>\n

To provide antioxidant protection, 90 mg\/day for adult men and 75 mg\/day for adult women is recommended for those in optimal health<\/span>.[50]<\/sup><\/a> Others are recommended to increase their daily intake.<\/p>\n

\n
\n

Did You Know?<\/strong><\/p>\n<\/header>\n

Smoking increases oxidative stress and metabolic turnover of Vitamin C.<\/div>\n<\/div>\n

The Tolerable Upper Intake Level (UL) for adults is set at 2 g\/day, as gastrointestinal disturbances such as diarrhea can occur for some people above these levels.[51]<\/sup><\/a><\/p>\n

It is important to note that while Vitamin C deficiency results in impaired immunity and higher susceptibility to infections, when someone has an active infection, inflammation, or wounds, Vitamin C levels are significantly impacted due to increased metabolic requirements for healing. \u00a0Thus a person who has increased metabolic demand would need higher doses of Vitamin C overall.[52]<\/sup><\/a><\/p>\n

Vitamin A<\/strong><\/p>\n

The effects of Vitamin A on our bodies aren\u2019t generally well known by many people. Some people know that it\u2019s imperative for your vision, or that if you use it topically (Retin-A) it can help acne and wrinkles, but did you know that it is crucial for the immune system? Vitamin A plays a critical role in enhancing immune function and helping the antibody response.[53]<\/sup><\/a> \u00a0Vitamin A is also known as an anti-inflammatory vitamin, promoting cell growth and differentiation, and protecting epithelium and mucus integrity in the body.[54]<\/sup><\/a> We know that the gut is the foundation of our immune system, so Vitamin A plays a huge part in maintaining its integrity and mucosal defenses as well as keeping inflammation in check.<\/p>\n

Vitamin A is a fat-soluble vitamin, thus the body stores excess amounts, mostly in the liver. This means that excess Vitamin A supplementation can have significant toxic ramifications, most notably for the liver. Vitamin A deficiency is rarely seen in developed countries, but is common in developing countries.[55]<\/sup><\/a> Vitamin A is found in many foods such as eggs, dairy products, and organ meats such as liver. Other sources are foods rich in beta-carotene (provitamin A), the nutrient that is converted to Vitamin A in our bodies, such as green leafy vegetables and orange and yellow vegetables and fruits.<\/p>\n

Herbals<\/strong><\/p>\n

There are two herbals worth mentioning due to their significant antiviral and antibacterial properties that are well documented in science.<\/p>\n

Black elderberry<\/strong> (sambucus nigra), is one of the most commonly used medicinal plants in the world, and traditionally, Indigenous people used it to treat colds, fever and rheumatism.[56]<\/sup><\/a>\u00a0 Elderberry has demonstrated potent antibacterial and antiviral potential against bacterial upper respiratory infections as well as the influenza virus.[57]<\/sup><\/a> [58]<\/sup><\/a> [59]<\/sup><\/a><\/p>\n

\"\"<\/a>
Figure 10.4 Elderberry<\/figcaption><\/figure>\n

Echinacea<\/strong>, mainly the E. purpurea species, has been used for centuries to treat respiratory tract infections and inflammatory conditions.[60]<\/sup><\/a> Echinacea has been shown in research to reduce the duration and severity of cold symptoms.[61]<\/sup><\/a> Research has also illustrated the anti-inflammatory, anti-viral and anti-bacterial effects of echinacea.[62]<\/sup><\/a><\/p>\n

\"\"<\/a>
Figure 10.5 Echinacea<\/figcaption><\/figure>\n

So there you have it! You’ve learned a lot about your immune system, it’s connection to stress, and your ability to bolster it through healthy living and natural means. Take this knowledge to heart, and tie it in with the information to follow. Your body will thank you!<\/p>\n

Media Attributions<\/h2>