The 5 Best Vitamins for Boosting Your Immune System

Enhancing Your Immune System Series

By: Laura Tetrault 
Reading Time: 6 mins

 Updated: March 7, 2022

We’ve been exploring things that you can do to boost your immunity in this article series and you can read more about your immune system, how laughter, stress, sleep and even your gut health can affect it. You can also get more information about helpful foods and supplements on our blog.

Make sure to speak with your doctor before beginning any new supplement routine. Some vitamins and supplements may cause adverse reactions when combined with different medications.

Best Vitamins to Boost Your Immune System

There is value in knowing which vitamins and supplements can provide support to your immune system, how they work and where you can get more of them into your diet. That’s the aim of this article. We’ll investigate vitamins now and get to know the supplements in our next article.

A Quick Review of Your Immune System

In case you missed our introduction to the immune system - here’s a quick summary.
Your immune system has four major components:
  1. Homeland Security - your skin, tears, mucus and saliva work to keep invaders out.

  2. Recruitment - your thymus and bone marrow make the blood cells to populate your body’s standing army.

  3. MI-6 - your spleen and lymphatic system identify invaders (bacteria and viruses) and eliminate them.

  4. The Infantry - the white blood cells your body makes to seek and destroy invaders. These cells have specific tasks and targets depending on what type of cell they are.

The invaders we want to keep out are bacteria - living organisms that eat and reproduce often in a specific area, and viruses which are non-living and seek out host cells in order to reproduce themselves.

How Vitamins Can Work With Your Immune System

Experts differ on the efficacy of supplementing your diet with vitamins, but here’s what they generally agree on.

Vitamins A, C, D, and E and the mineral zinc have a relationship to your immunity levels and immune system function. But, supporting and improving your immune system takes time and thoughtful choices in your diet and supplements, so don’t expect an over-night, silver bullet solution.

Many studies also show that your immune system suffers when it lacks enough of the essential nutrients that your body needs, and that people who are deficient in vitamins C and D in particular have higher risk of infections including respiratory illnesses like pneumonia. 

Supportive roles that vitamins and minerals play

  • Help your body do its job
  • Lower your risk of infections (respiratory)
  • Reduce the severity of illness
  • Aid recovery time
  • Some reduce the length of time you’re sick (zinc)
  • Some help symptoms (zinc)
  • Some help produce and activate t-cells

Types of Vitamins that could help and why

Vitamin D

Vitamin D is generally absorbed through your skin through sunlight and it supports the immune system by stimulating your immune cells and enhancing the pathogen-fighting effects of your white blood cells. Your body makes antimicrobial proteins that kill bacteria and viruses.“If you don’t have adequate vitamin D circulating, you are less effective at producing these proteins and more susceptible to infection,” says professor of emergency medicine at the University of Colorado School of Medicine, Dr. Adit Ginde.

Vitamin D doesn’t protect you from getting a virus if you’re exposed, but it could reduce the severity of the illness and help make recovery easier. Additionally, study results published by the World Health Organization state that "vitamin D supplementation significantly decreased the risk of respiratory tract infections".  Those who had adequate vitamin D levels also “lowered [their] infection risk.” You might ask, how would I know if I have a Vitamin D deficiency? Chances are that if you work indoors, live in a northern country or never leave the house without sunscreen your Vitamin D levels might be suboptimal. According to the National Library of Medicine, over 41% of the population have a Vitamin D deficiency.

How much Vitamin D do you need?


If you're looking for a supplement, we recommend Genestra's Vitamin D-Mulsion 1000IU. It has a pleasant citrus flavour which is a nice change from the fishy flavour some capsules have and way better taste than cod liver oil! The liquid form also makes it easier for your body to absorb and use.  

Vitamin C

Taking Vitamin C at the onset and during an illness isn’t a new idea. We know that supplementing with it can reduce the length and severity of upper respiratory tract infections. But did you know that it is also necessary for cellular death? Cellular death helps keep your immune system (and its standing army) at its best by removing old, worn out ‘soldiers’ and replacing those cells with new ones. Additionally, Vitamin C is an antioxidant, and helps reduce inflammation. One of the more severe symptoms associated with COVID-19 is lung inflammation, which can lead to respiratory distress or even death. So how much vitamin C do you need? Experts say that your upper limit is about 2000 mg per day. Generally supplemental daily doses range between 250 and 1000 mg.

Vitamin B

The B Complex vitamins play an important role in maintaining cell health and preventing infections, but many adults are deficient in them. Vitamin B6, in particular, is thought to be essential to keeping your immune system working well. You can get the B vitamins in fortified cereals, as part of your daily diet or as a supplement.

Vitamin E

Like vitamin C, vitamin E is an antioxidant and helps reduce inflammation in the body. Vitamin E protects your cells from damage caused by free radicals. And in case you aren’t exactly clear on what free radicals are, Dr. Lauri Wright describes them “as waste products from various chemical reactions in the cell that when built up, harm the cells of the body.” Vitamin E is vital for maintaining healthy skin - a large part of our visible immune system, and also for supporting our internal immune system.


Up to 30% of older adults are considered to have a zinc deficiency. It affects approximately 2 billion people worldwide. There are many studies suggesting that zinc supplements may protect against respiratory tract infections and reduce the duration of an infection if you have already have one. Healthline reported in a 2020 article that in a 2019 study, children with acute lower respiratory tract infections (ALRIs), taking 30 mg of zinc per day decreased the total duration of infection and the duration of the hospital stay by an average of 2 days, compared with a placebo group. 75mg is the recommended daily dose for zinc, but taking more than 150 mg of zinc could cause zinc toxicity, so make sure to speak with your doctor before starting a new regimen.

What kinds of food should I eat?

  • Vitamin A and beta-carotene: pumpkin, squash, carrots, spinach, sweet potatoes, cantaloupes, dark leafy greens, and mangoes

  • Vitamin C: citrus fruits, strawberries, bell peppers, cauliflower, broccoli, tomatoes, sweet potatoes, and asparagus

  • Vitamin E: vegetable oil, almonds, whole grains, wheat germ, sweet potatoes, and yams

  • Vitamin D: cod liver oil, salmon, sardines, tuna, shiitake mushrooms, egg yolk fortified milk or yogurt, fortified orange juice, fortified cheese 

  • Zinc : Red meat, shellfish, legumes, seeds (hemp, pumpkin, squash, sesame), nuts (cashews), dairy (cheese and milk), eggs, whole grains (wheat, quinoa, oats), potatoes, dark chocolate. 



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