It’s that time of the year again – winter Holidays are here!

Not only are we surrounded by delicious food and beautiful decorations, but it’s also winter and we need to keep our immune system healthy by eating what’s good for our body. Let’s look at ways we can reduce our chances of falling sick this winter, while also staying healthy and happy.  First up is our immune system. Respiratory tract infections are highly opportunistic and often occur when we have a reduced immune function. So, what vitamins and minerals should we pay attention to during this winter? Let’s look at some facts below! 

Vitamin D 

It plays an important role in regulating the immune system. Research studies have associated low levels of vitamin D with poor immune function and increased respiratory infection rates.  Will supplementing help reduce our chances of getting a respiratory infection? Studies have actually found that unless you have really low levels of vitamin D, supplementing will not provide a huge benefit. Health Canada recommends that adults over 50 years old to take vitamin D supplements.  

But what should you do if you are younger?  

  • Make sure to include foods with vitamin D every day, such as egg yolks, liver, red meat, salmon, sardines, mackerel, fortified cow’s milk and fortified plant-based milk. 
  • Talk to your doctor with regards to supplementing with vitamin D! 

Vitamin C  

It helps immune cells form and function. It has also been shown to help prevent infections caused by microorganisms. Will supplementing help ward off colds? Studies have shown that if you already have a cold and start taking vitamin C, there won’t be much of a benefit. If you are taking vitamin C regularly, this can lead to reduced duration of colds and decreased symptom severity – especially if you are an athlete.  

3 tips to incorporate vitamin-C rich foods into your diet: 

  • Have your morning cereal or oatmeal with berries, mango, kiwi, or oranges 
  • Load up half your plate with vegetables such as broccoli, peppers, tomatoes, or beets 
  • Toss some orange or grapefruit slices into a salad for some extra vitamin C or use lemon as part of your salad dressing! 


Zinc plays many roles in the body, such as supporting antioxidant enzymes, brain function, and the immune system. Zinc lozenges has been shown to reduce the duration of a cold by 2-4 days when 75–95 milligrams are taken per day, starting on the day of symptom onset. However, because this dose is well above the safe upper limit of 40mg/day, you can experience nausea, vomiting, diarrhea, stomach cramps, or headaches.  

So, what should you do? 

  • Incorporate foods high in zinc on daily basis, such as lentils, cheese, pork, beef, and turkey 
  • If you are eating a variety of foods and have no health conditions, you shouldn’t be taking zinc supplements.  
  • Some reasons people may need a zinc supplement include recent digestive tract surgery, Ulcerative Colitis, Crohn’s disease, chronic liver disease.  
  • If you are following a vegan or vegetarian diet and not eating a variety of plant based protein sources with zinc, speak to your healthcare provider about zinc supplements.  

Natural Health Products 

The name “natural health products” does not necessarily mean these are safe for everyone – they still have side effects. Keep in mind that evidence on the effects of natural health products is scare, so talk to your health care provider about any natural health products that you are currently taking or planning to take.  

  • Echinacea – a herb traditionally used to ease cold symptoms. It can interact with immunosuppressive drugs and other medicine.  
  • Elderberries – known for their antioxidant properties, these have been used to treat colds. The plant is poisonous, and the berries can be dangerous if not cooked properly.  
  • Probiotics – studies are still ongoing on the efficacy of probiotics to increase the protective immune response of the flu vaccine.  

Best practices to keep you healthy this holiday season 

  1. Drink plenty of fluids 
  2. Get a good night sleep
  3. Have a plan to manage stress 
  4. Move your body daily through exercise
  5. Wash your hands and avoid touching your eyes, nose, and mouth – no nail biting!  
  6. Eat nutrient dense foods daily 


(1) Braga, Vinícius Lopes, et al. “What Do Cochrane Systematic Reviews Say about Probiotics as Preventive Interventions?” Sao Paulo Medical Journal, Associação Paulista De Medicina – APM, 2017, 

 (2) Hemilä, Harri, and Elizabeth Chalker. “Vitamin C for Preventing and Treating the Common Cold.” The Cochrane Database of Systematic Reviews, John Wiley & Sons, Ltd, 31 Jan. 2013, 

(3) Hemilä, Harri, and Elizabeth Chalker. “The Effectiveness of High Dose Zinc Acetate Lozenges on Various Common Cold Symptoms: A Meta-Analysis.” BMC Family Practice, BioMed Central, 25 Feb. 2015, 

(4) Prietl, Barbara, et al. “Vitamin D and Immune Function.” MDPI, Multidisciplinary Digital Publishing Institute, 5 July 2013, 

(5) Vuichard Gysin D; Dao D; Gysin CM; Lytvyn L; Loeb M; “Effect of Vitamin D3 Supplementation on Respiratory Tract Infections in Healthy Individuals: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” PloS One, U.S. National Library of Medicine, 2016, 

(6) “What You Need to Know about Zinc and Immunity.” What You Need to Know about Zinc – Unlock Food, 2021, 

Wednesday, December 22, 2021 in
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