Supporting Your Immune System with Supplements

Reviewed by Aleksandra Morgan, CNP

With colder weather approaching and cold and flu season underway, a strong and resilient immune system is our first line of defense against infections and illnesses. One way to support and enhance your immune system is through proper nutrition and supplementation, including essential vitamins and minerals. Let’s explore the benefits of Vitamin D, Vitamin C, Zinc, medicinal mushrooms, Quercetin and NAC in bolstering your immune system. 

Vitamin D

  • Vitamin D is often referred to as the "sunshine vitamin" because it is synthesized in the skin when exposed to sunlight. While sunlight exposure is a natural source of Vitamin D, it's important to maintain appropriate levels through diet and health supplements to ensure a robust and resilient immune system. 
  • Vitamin D helps activate immune cells, such as T cells and macrophages, which are responsible for identifying and eliminating pathogens like bacteria and viruses. 
  • It regulates the production of inflammatory proteins, reducing the risk of chronic inflammation, which can weaken the immune system over time. 

Considering that sun exposure can have negative effects on our skin health and the fact that in Canada we do not get enough sun exposure from October to May to maintain adequate levels of vitamin D, supplementation becomes a necessity. Vitamin D is important not only for our immune health but also our bone health, mood, and energy as well as a healthy inflammatory response. (Please note: When it comes to bone and heart health, it is important to take vitamin D with vitamin K to ensure that the circulating calcium goes into the bones instead of depositing into soft tissues and/or arteries.) 

Here are some of our favorites; 

  XYMOGEN D3 LIQUID features 1000IU per drop that can be taken on its own or added to smoothies. 
AOR VITAMIN D3 2500 offers easy to swallow, higher dose vitamin D great for correcting a vitamin D deficiency. 


Vitamin C

Vitamin C, also known as ascorbic acid, is famous for its immune-boosting properties. This vitamin is a potent antioxidant, meaning it helps protect cells from oxidative stress and damage caused by free radicals.  

Here's why Vitamin C is essential for a robust immune system: 

  • By neutralizing harmful free radicals, Vitamin C reduces cellular damage and helps your immune cells function optimally. 
  • It supports the production of collagen, a protein that plays a critical role in wound healing and maintaining the integrity of your skin and mucous membranes. 

To increase your Vitamin C intake, include citrus fruits, strawberries, kiwi, broccoli, and bell peppers in your diet or include a vitamin C supplement. 

Here are our favorites: 

  PROVITA ORGANIC ACEROLA VITAMIN C is a whole food vitamin C for better absorption and it is gentle on the stomach. 
DESIGNS FOR HEALTH LIPOSOMAL VITAMIN C offers superior absorption for therapeutic dosing. 



Zinc is a vital mineral that is involved in numerous aspects of immune system function. It's required for the development and activation of immune cells, making it an indispensable nutrient for immune health.  

Here's why Zinc is crucial for your immune system: 

  • Zinc helps immune cells communicate and function efficiently, ensuring a robust immune response. 
  • Zinc has been shown to inhibit the replication of certain viruses, potentially reducing the severity and duration of viral infections. 

To incorporate more Zinc into your diet, consume foods like lean meats, seafood, nuts, seeds, whole grains, and legumes. However, be mindful not to overconsume Zinc, as excessive intake can lead to adverse effects.
(Please note: If you are taking Zinc for an extended period of time, ensure you are also getting enough copper in your diet or in your multivitamin.

Here are our favorites: 

  AOR ZINC-COPPER BALANCE provides a balanced ratio of zinc and copper to maintain the balance of these two minerals. 
CANPREV ZINC 30 IMMUNE + VITAMIN C is in a liquid format for faster absorption. 


Medicinal Mushrooms

Medicinal mushrooms have been used for centuries in traditional medicine systems for their immune-boosting properties. Some of the most well-known medicinal mushrooms include Reishi, Shiitake, and Maitake. They contain compounds like beta-glucans and polysaccharides that have immune-enhancing effects: 

  • Beta-glucans in mushrooms stimulate immune cells, improving their ability to recognize and destroy pathogens. 
  • Medicinal mushrooms can modulate the body's inflammatory response, preventing excessive inflammation that can harm the immune system. 

You can enjoy medicinal mushrooms such as shiitake in various forms, like capsules, extracts, or by adding them to your soups and stir-fries. 

Here are some of our favourites:

  CYTO-MATRIX MUSHROOM MATRIX is a blend of 7 medicinal mushrooms in powder form that can be added to smoothies. 
NFH MUSHROOM COMPLEX SAP in capsule form featuring 4 hot water extracted medicinal mushrooms. 



Quercetin is a natural flavonoid found in a variety of fruits, vegetables, and grains, and known for its immune supporting benefits. One of its key immune-boosting mechanisms is its ability to act as an antioxidant, helping to neutralize harmful free radicals that can damage immune cells and impair their function. 

  • Quercetin has been shown in some studies to modulate the immune response by reducing the production of pro-inflammatory molecules, which can help maintain a balanced and effective immune system. 
  • Quercetin also enhances the activity of immune cells such as natural killer (NK) cells and T lymphocytes, which play pivotal roles in identifying and eliminating pathogens, ultimately promoting overall immune system health. 

Here are our favorites: 

  BIOCLINIC NATURALS EMIQ® ACTIVATED QUERCETIN that offers 40 times greater absorption than regular quercetin. 
CANPREV LIPOSOMAL QUERCETIN features highly absorbable quercetin in liquid form. 



N-acetylcysteine (NAC)

NAC supports the immune system primarily through its role in replenishing glutathione, a powerful antioxidant naturally produced in the body. 

Glutathione is crucial for maintaining a balanced immune response, as it helps control inflammation and protects immune cells from oxidative stress and damage. 

NAC has been shown to reduce the severity and duration of respiratory infections, including those caused by viruses. 

NAC may also help thin mucus in the respiratory tract, making it easier to clear and potentially alleviate symptoms of conditions like bronchitis and chronic obstructive pulmonary disease (COPD). 

Here are our favorites: 

PRAIRIE NATURALS NAC features a high dose of 1000mg of NAC per capsule. 
CANPREV NAC+ featuring 600mg of NAC with added L-Glycine and selenium as additional support for glutathione production. 


Supporting your immune system with proper nutrition and supplementation is a proactive way to enhance your overall health and well-being. Vitamin D, Vitamin C, Zinc, medicinal mushrooms, Quercetin and NAC are valuable additions to your immune-boosting arsenal. Remember to maintain a balanced diet, get regular exercise, manage stress, and get adequate sleep to ensure your immune system is always ready to protect you from infections and illnesses. A healthy lifestyle, combined with these immune-boosting nutrients, can help you stay resilient and vibrant all year-round. 

Disclaimer: The information provided in this blog is for educational purposes only and should not be considered as a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider regarding any medical condition, dietary changes, or supplementation.