Immune System Part 2: Common Nutrient Deficiencies that Affect it’s Strength.
Make sure to read Immune System Part 1 here. This content has been simplified to give an overall picture with some details. Immunology is complicated and made up of many pathways that are not discussed here fully.
Your immune system never sleeps. It is constantly working to protect the body from infection, diseases and repairing injuries. Subsequently, your body requires a substantial amount of energy and nutrition in order to work properly; even more so when your immune system needs to ramp up it’s effectiveness. Unfortunately, many North Americans are deficient in some important nutrients that are needed for a healthy functioning immune system. The CDC and Health Canada report that at least 10% of the North American populations have nutrient deficiencies (1,2). Both of these reports come from either a survey on dietary intake or laboratory blood tests; these methods are statistically derived to see how many people are deficient in specific nutrients. The optimal nutritional needs for the body and its immune system can change and may be higher or lower at times and vary by the individual.
There are some variations between US and Canadian populations in which nutrients are inadequate as well as in different age groups. What is found across the board is a deficiency in Vitamin D, which is not surprising as we spend a lot of our time indoors, even more so in winter months. Other nutrients found low in Canadian diets are Magnesium, Vitamin A, Zinc, Calcium and Vitamin C. So which of these are important in our immune systems?
Vitamin D
Most people hear about how important Vitamin D is for their health, especially for the immune system. But why? Well first of all, the active form, Vitamin D3 (1,25-dihydroxyvitamin D3) is technically a steroid hormone (not to be concerned/confused with conventional steroids used in body building). As a hormone, Vitamin D3 regulates a lot of processes in the body by activating receptors on cells. Some of these are found on our immune cells to tell them what to change into and what to do (as simply as I can put it) and is also a huge regulator of two antimicrobial proteins in the body, cathelicidin and defensin (3). All important aspects of keeping the innate and adaptive immune responses in check and in balance. Because of its action, a deficiency in this vitamin has shown to increase the chances of getting lung infections (4). This explains why the winter seasons show more incidences of cold/flu, on top of other contributing factors, such as temperature, crowded indoor spaces, etc. The dosage of this sunshine vitamin is important as you also do NOT want to overdo it. High dosages may increase risk of other conditions (5). So it is important to check for vitamin D levels in the blood prior to supplementation. Which in Canada is not covered by provincial health care plans.
Vitamin A
Another key vitamin in both our innate and adaptive immune responses. Mucous membranes in your lungs, digestive system and any outer surfaces rely on this vitamin for integrity and structure. It acts by strengthening our physical defense against outside invaders. Our bodies convert Vitamin A to retinoic acid, another steroid that regulates a lot of pathways. Hundreds of genes are expressed and controlled directly/indirectly by retinoic acid. Of those, many influence the development and function of both innate and adaptive immune cells. An important function that is improved by retinoic acid is the antibody and antigen responses by B and T cells (6). This allows for recognition of foreign invaders that have passed the physical barriers and are in our system, such as viruses. A deficiency in this vitamin is seen to increase susceptibility of various infections (4). Monitoring the intake of this vitamin is crucial, as there are various forms of Vitamin A and high dosages can be toxic!
Vitamin C
Chances are many of you are already supplementing with vitamin C at the recommendation of a family member, a friend, or even your barista who may have suggested you start taking it daily. Vitamin C is one of the most popular vitamins when it comes to cold/flu prevention but also the most controversial. Ascorbic acid (Vitamin C) is produced in the bodies of many in the animal kingdom, but we humans have lost that ability. With that, extreme deficiency of this vitamin causes scurvy (swollen gums, loose teeth, poor wound healing and infection). Approximately 10% or more of the population receives just below the recommended daily intake, which makes them susceptible to infection and a lowered immunity (2). The research out there keeps going back and forth on it’s effectiveness on lowering cold/flu symptoms or in prevention, as well as in intravenous (IV) use for lung related conditions (which does show some promising results that need more clinical investigation) (7,8). It is known that Vitamin C does help with collagen synthesis which is important in creating strong barriers against the outside world (9). It’s protectant immune functions is well observed in the ability of Vitamin C to reduce oxidative damage in the body that our immune cells create when killing off invaders. This in turn allows our immune cells to be more effective and do their job without harming us. Having sub-optimal levels of this vitamin regardless is not a good idea. So, always make sure your diet always contains citrus fruit or consider supplementation. High doses aren’t absorbed fully and should be taken in divided dosages. Otherwise you just pee it out. It is also important to note that large, non-divided dosages can cause diarrhea and digestive upset.
Zinc (Zn)
Probably one of my favourite supplements as it is important for so many functions, especially in skin conditions related to acne and inflammation. Incredible overall improvements are seen with zinc supplementation as most individuals are either marginally deficient or requiring more in their system. Zinc is not stored in the body so it is needed to be regularly consumed through diet or supplements. Having lowered amounts of zinc in your system really screws up your immunity (10). And with two main sources being oysters and beef, it is common to see a deficiency. With age, your ability to absorb zinc becomes lowered. Zinc is crucial for keeping up your immune cell numbers, creating cell integrity and lowering inflammation. T cells which create receptors on themselves to recognize already infected cells are improved in function and count by zinc supplementation, especially if one is already deficient. Not only is it essential in that adaptive immune response but it also shows to be important for the function of innate immune cells too (11). Lots of this information and research didn’t start until around the 1960s when major deficiencies were seen in Iranian males and the effects that came along (12). Although over 40 years of knowing that zinc is a common deficiency, it has largely been ignored. A lot of the mechanisms/pathophysiology of zinc is still unknown. Long-term supplementation of zinc can cause copper deficiency, so small dosages of copper is usually advised with supplementation over 4 months (13).
Magnesium (Mg)
Most athletes can do with a little more magnesium in their diets as it is beneficial for relaxing strained and spastic muscles. This mineral is a co-factor to over 300 enzymes in the body, so it is bound to be important for immune system function. Unfortunately, it seems that a lot of the population is ‘potentially’ deficient (2). Because Magnesium is involved in so many processes it makes it a lot harder to study, including deficiencies. The observation that Mg intake in North American populations is deficient is solely due to looking at what people eat. When it comes to what amounts of Mg should be in your system and the recommended intakes, it varies across all scientific research (14). Many rat studies show huge negative effects on the immune system when deficient of Mg but in humans the research is still somewhat lacking. The best research is seen with intense exercise and athletes who are with or without Magnesium supplementation. Those that did showed less likely to catch a cold/flu (15). Improvements in asthma with sufficient Mg intake has also been studied. This is mostly due to the fact that this mineral is part of many anti-inflammatory pathways and involved in relaxing smooth muscles (16). The study on allergies, being an autoimmune condition, indicates that this mineral has promising immune function. Magnesium is on this list because it is one of those nutrients that is always talked about but also a little misunderstood. It is a cornerstone nutrient in our bodies with vast effects. Found highest in dark leafy vegetables, most of the North American population is highly likely to be deficient as many simply do not eat enough vegetables.
There you have it. Nutrient deficiencies are a big part of an impaired immune system! And they are more common than you think. You are likely to hear a lot about taking this or that to boost immunity without much talk on making sure your bottom-line functions are supplied first. It is important to be aware of these common deficiencies and the nutrients that are involved. Natural health is a complex topic and it seems that these days everyone is an expert on it due to a few simple google searches. Make sure to chat with an educated healthcare practitioner about how to go about your health before taking someone’s unsolicited advice, while also educating yourself!
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References:
1) National Health and Nutrition Examination Survery, NHANES. “National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population 2012.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 27 Mar. 2012, www.cdc.gov/nutritionreport/index.html. Accessed March 27, 2020.
2) Health Canada. “Do Canadian Adults Meet Their Nutrient Requirements Through Food Intake Alone?” Government of Canada. 2012. H164-112/3-2012E-PDF. https://www.canada.ca/en/health-canada/services/food-nutrition/food-nutrition-surveillance/health-nutrition-surveys/canadian-community-health-survey-cchs/canadian-adults-meet-their-nutrient-requirements-through-food-intake-alone-health-canada-2012.html. Updated 2012. Accessed March 28, 2020.
3) Weber, Günther et al. “Vitamin D Induces the Antimicrobial Protein hCAP18 in Human Skin.” Journal of Investigative Dermatology. 2005;125(5):1080-1082. https://www.jidonline.org/article/S0022-202X(15)32265-X/fulltext. doi: 10.1111/j.0022-202X.2005.23687.
4) Prentice S. “They Are What You Eat: Can Nutritional Factors during Gestation and Early Infancy Modulate the Neonatal Immune Response?” Front Immunol. 2017;8:1641. Published 2017 Nov 28. doi:10.3389/fimmu.2017.01641
5) Hansen KE. “High-dose vitamin D: helpful or harmful?” Curr Rheumatol Rep. 2011;13(3):257–264. doi:10.1007/s11926-011-0175-9
6) Balmer J., Blomhoff R. “Gene expression regulation by retinoic acid.” Journal of Lipid Research. 2002;43:1773-1808. doi: 10.1194/jlr.R100015-JLR200
7) Hemilä H. “Vitamin C and common cold-induced asthma: a systematic review and statistical analysis.” Allergy Asthma Clin Immunol. 2013;9(1):46. doi: 10.1186/1710-1492-9-46.
8) Hemilä H., Chalker E. “Vitamin C for preventing and treating the common cold.” Cochrane Database Syst Rev. 2013;(1):CD000980. doi: 10.1002/14651858.CD000980.pub4.
9) Haryanto B., Suksmasari T., Wintergerst E., Maggini S. “Multivitamin supplementation supports immune function and ameliorates conditions triggered by reduced air quality.” Vitam Miner. 2015;4:1–15. doi:10.4172/2376-1318.1000128.
10) Ibs K-H, Rink L. Zinc. In: Hughes DA, Darlington LG, Bendich A, eds. “Diet and Human Immune Function.” Totowa, New Jersey: Human Press Inc.; 2004:241-259.
11) Shankar AH, Prasad AS. “Zinc and immune function: the biological basis of altered resistance to infection.” Am J Clin Nutr. 1998;68(2 Suppl):447S-463S. doi: 10.1093/ajcn/68.2.447S.
12) Prasad AS, Halsted JA, Nadimi M. “Syndrome of iron deficiency anemia, hepatosplenomegaly, hypogonadism, dwarfism and geophagia.” Am J Med. 1961;31:532–546. doi: 10.1016/0002-9343(61)90137-1.
13) Duncan A. et al. “The risk of copper deficiency in patients prescribed zinc supplements.” J Clin Pathol. 2015;68(9):723-5. doi: 10.1136/jclinpath-2014-202837.
14) EFSA Panel on Dietetic Products. “Nutrition and Allergies (NDA) Scientific opinion on dietary reference values for magnesium.” EFSA J. 2015;13:4186. doi: 10.2903/j.efsa.2015.4186.
15) König D., et al. “Zinc, iron, and magnesium status in athletes--influence on the regulation of exercise-induced stress and immune function.” Exerc Immunol Rev. 1998;4:2-21. PMID: 9644092.
16) Fantidis P., et al. “Intracellular (polymorphonuclear) magnesium content in patients with bronchial asthma between attacks.” J R Soc Med. 1995;88(8):441-5. PMID: 7562826.