Immune Hacks for the Holiday season

By Dr. Emily McManus

We know everyone wants to be feeling their best for the holiday and as chiropractors we want that too. In addition to being able to celebrate with loved ones, we know it’s easier for people to take care of their bones, joints, and muscles with exercises and activities if they’re feeling well rather than fighting a cold or flu. Read on for ways to make sure you feel your best this holiday season.

  1. Vitamin D – Aside from being really good for our bones, Vitamin D plays a huge role in immune functioni and according to recent data, 4 in 10 Canadians do not meet the minimum recommended daily intake (RDI) in the winter.ii Vitamin D helps the body produce proteins that have antiviral effects and it reduces inflammation.iii Since the biggest source of Vitamin D is sunlight, deficiency is even more common during the winter months. It is difficult to get adequate levels from food sources – skins of fattier fish (i.e. mackerel) and cod liver oil are some of the best sources as well as liver and egg yolkiv. In Canada, many commonly consumed foods (i.e. margarine, juice etc.) are fortified with vitamin D, however; it is unlikely to get more than 100 IU from these sources. If you don’t already take a vitamin D supplement, this is one of the least expensive and most effective ways to increase your immunity (and lots of other important bodily functions including building strong bones)! For the recommended amount of Vitamin D, see the table below.
Age group Recommended Dietary Allowance (RDA) per day Tolerable Upper Intake Level (UL) per day (aka don’t consume more than this)
Infants 0-6 months 400 IU  (10 mcg) 1000 IU (25 mcg)
Infants 7-12 months 400 IU  (10 mcg) 1500 IU (38 mcg)
Children 1-3 years 600 IU (15 mcg) 2500 IU (63 mcg)
Children 4-8 years 600 IU (15 mcg) 3000 IU (75 mcg)
Children and Adults
9-70 years
600 IU (15 mcg) 4000 IU (100 mcg)
Adults > 70 years 800 IU (20 mcg) 4000 IU (100 mcg)
Pregnancy & Lactation 600 IU (15 mcg) 4000 IU (100 mcg)

Health Canada: Daily Recommended Intakes for Vitamin Dv


  1. PREbiotics and PRObiotics – Prebiotics, nutrients that feeds healthy bacteria in our intestinal system, and probiotics, foods containing live cultures that help repopulate our intestinal system with healthy bacteria are both immune Both increase absorption in our GI tracts, meaning we take better advantage of the other healthy foods we eat. Prebiotics have the added benefit of improved bone mineral content (stronger bones).vii
  • Prebiotics (inulin, oligofructose, sugar alcohols etc.) are available as supplements, or in lots of healthy vegetables such as dandelion greens, radicchio, frisee, endives, onions, artichoke, asparagus, chicory, jicama and garlicviii,ix
  • Consume fermented foods on a regular basis or take a probiotic supplement. Foods such as certain yogurts, kefir, kombucha, and sauerkraut are cultured with probiotics; healthy bacteria that help maintain a healthy digestive tract and improve nutrient absorption, which in turn improve health. x


  1. Garlic – Garlic is antimicrobialxi, antiviral and antifungalxii, a triple threat. Try adding a bit of extra fresh garlic to your favourite eats this winter.


  1. Tea – Tea is hydrating and soothing. Both green and black teas contain strong antioxidants, called flavonoids that bolster our immune systemsxiii. For extra benefit add ginger or honey or both. Ginger helps us fight rhinovirusesxiv, one of the most common families of cold causing viruses. Honey helps fight bacteria and virusesxv.


  1. Sleep – Quantity and quality is important. Lack of enough or good sleep can weaken our body’s defensesxvi and it’s natural to sleep more during the darker months because we produce more melatonin, a hormone involved in sleep initiationxvii. How much sleep do you need? It varies according to age – see the chart below. Sleep needs includes hours sleeping at night and while napping.



To ensure sound and restorative sleep:


    1. Lights out and eyes shut by 10:30pm. Many people experience a second wind if they’re awake after 11:00pm.
    2. Limit or eliminate caffeine intake and other stimulants after lunchtime. Stimulants can increase cortisol levels late in the day, which normally fall during the late afternoon and evening. If you need a boost in the afternoon, try green tea or back to basic energy boosts such as water or a brief walk.
    3. Turn off electronics – The light from TVs, computers, smartphones etc. is can be over stimulating when our nervous system needs to wind down in preparation for sleep.


  1. Homemade soup – Sound familiar? Soup made from homemade bone broth has many benefits including strengthening our immune systems.xviii It’s no surprise we often crave it at this time of year. Try as much as possible to use organic and grass-fed meats to make your broth. As a bonus, animal based broth itself contains high amounts of proline and glycine, amino acids that are both building blocks for healthy connective tissue and have anti-inflammatory properties soothing for those that might already feel a bit under the weather.


  1. Mushrooms – Eating mushrooms, (especially shitake, maitake, and reiki varieties), increase production of cells that fight infection and generally support our immune systems.xix If you’re following a vegetarian diet, mushrooms are a good immune support alternative to homemade bone broth soup.


  1. Drink up! Water that is – As we increase the heat in our homes we also need to increase our water intake. Winter air, especially inside, is often drier and our cells function best with optimal hydration. If you don’t already, try starting your day with water and fresh lemon slices or wedges. This boost of hydration and vitamin C will help start your day in one of the healthiest and most refreshing waysxx. Please note, it’s important to limit alcohol intake. With the holiday season often comes holiday cheer, keep in mind that alcohol can decrease immune function.xxi


  1. Laugh – Increased laughter has been shown to increase levels of certain antibodies and to increase levels of some immune cells. There is also evidence to show that laughter, a positive attitude and sense of humour promote sound sleep, increase blood flow and help regulate blood sugar levelsxxii.


  1. Exercise – Moderate exercise can boost the immune system by actually increasing production of immune cells as well as increasing the rate that they circulate through the body, giving them a better chance of recognizing and responding to bacteria or viruses earlier. Exercise can also increase are core temperature, which might help fend off infection. It’s important to note that too much or too strenuous exercise can actually depress the immune system.xxiii Heavy long term exercise can actually decrease production of white blood cells (the ones that help fight infection) and increase production of stress hormones (not good)!

Chances are you do some of the above already, so keep up the good work and pick a new healthy habit and get an early start on a resolution for the New Year. Have a happy, safe, and healthy holiday!




i Cantorna MT, Zhu Y, Froicu M & Wittke A (2004). Vitamin D Status, 1,25-dihydroxyvitamin D3, and the immune system. Am J Clin Nutr, 80(6): 17175-17205

ii Whiting SJ, Langlois KA, Vatanparast H, Greene-Finestone LS. The vitamin D status of Canadians relative to the 2011 Dietary Reference Intakes: An examination in children and adults with and without supplement use. Am J Clin Nutr 94(1): 128-35.

iii Ardizzone, S. Cassinotti, A. Trabattoni, D. Manzionna, G. Rainone, V. Bevilacqua, M. Massari, A. Manes, G. Maconi, G. Clerici, M. Bianchi Porro, G. Immunomodulatory effects of 1,25-dihydroxyvitamin D3 on TH1/TH2 cytokines in inflammatory bowel disease: an in vitro study. Int J Immunopathol Pharmacol. 2009 Jan-Mar; 22 (1): 63-71

 iv Dieticians of Canada (2012). Food sources of vitamin D.

v Health Canada (2012). Vitamin D and calcium: Updated dietary reference intakes.

vi Turner N (2012). The skinny on prebiotics versus probiotics in The Huffington Post.

vii Scholz-Arens et al. (2007). Prebiotics, probiotics, and synbiotics affect mineral absorption, bone mineral content, and bone structure. J Nutr, 137(3): 8385-8465.

viii Moshfegh et al. (1999). Presence of inulin and oligofructose in the diets of Americans. J Nutr, 129(7): 1407s-1411s.

ix McGruther J (2009). Prebiotics and probiotics. Nourished Kitchen.

x McGruther J (2009). Prebiotics and probiotics. Nourished Kitchen.

xi Ross ZM et al. (2001). Antimicrobial properties of garlic oil against human enteric bacteria: Evaluation of methodologies and comparison with garlic oil sulfides and garlic powder. Appl. Environ. Microbiol. , 67(1): 475-480.

xii Ankri S & Mirelman D (1999). Antimicrobial properties of allicin from garlic. Microbes and Infection, 1(2): 125-129

xiii Cao G. et al. (1996). Antioxidant capacity of tea and common vegetables. J. Agric. Food Chem., 44(11): 3426-3431

xiv Guaj J et al. (2012). The efficacy and safety of a patent pending combination of ginger and goldenrod extracts on the management of cold symptoms: A randomized, double-blind controlled trial. Food and Nutrition Sciences, 3: 1651-1657

xv Kwakman PHS (2010). How honey kills bacteria. The FASEB Journal, 24(7): 2576-2582

xvi Imen L & Opp MR (2009). How and why the immune system makes us sleep. Nature neuroscience reviews, 10: 199-210.

xvii Morera AL & Abreu P (2006). Seasonality of psychopathology and circannual melatonin rhythm. J Pineal Res., 41(3): 279-83

xviii Siebecker A, ND (2005). Traditional bone broth in modern health and disease. Townsend Letter, February/March 2005.

xix Borchers AT et al. (2004). Mushrooms, tumors, and immunity: An update. Expl Biol Med, 229(5): 393-406

xx Carr AC & Balz F (1999). Toward a new recommended dietary intake for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr., 69(6): 1086-1107.

xxi Romeo J et al. Moderate alcohol consumption and the immune system: A review. Br J Nutr., 98(Supp 1): S111-5.

xxii Hayashi T et al.. (2007). Laughter up-regulates the genes related to NK cell activity in diabetes. Biomed Res. 28(6): 281-5

xxiii Shepherd RJ & Shek PN (1999). Exercise, immunity, and susceptibility to disease: A j-shaped relationship? Phys Sportsmed. 27(6): 47-71.