6 Nutrients to Focus on For Immune Health

by Sarah Remmer

It’s that time of the year again! Cold and flu season is upon us and unfortunately, catching a bug is almost inevitable, especially if you’ve got school-aged children like me. And seriously – who has time to sit home and nurse an achy body back to health? Not me! As a busy mom of three kids, I can’t afford to get sick (even though my kids are germ monsters). There are a few key strategies to help prevent illnesses like regular hand washing, getting enough sleep, and eating a balanced diet full of vegetables, fruit, whole grains, protein-rich foods and healthy fats. But let’s face it: nobody is perfect. It’s hard to stay on track – even for me, the registered dietitian! Sometimes I need help in the sleep department (melatonin strips have been a game changer for me), and I also need to remind myself to include enough immune-friendly foods and nutrients, especially during cold and flu season. Here are a few important immune-boosting nutrients I try to focus on during the winter months to help me stay healthy, and away from the tissue box.


We all know the benefits of protein, but when it comes to immune health, it’s a game changer! If you’re not consuming enough protein in your diet, whether it’s animal-based or plant-based, you are going to end up with a weakened immune system. Protein helps to build and repair the body’s tissues and it helps fight viral and bacterial infections! Bottom line is, our immune system relies on protein. So, make sure that you include some in each meal and snack. I’ve been trying to incorporate more plant-based protein in my diet for a few reasons, including immune health, but also because plant-based sources of protein like beans, lentils, legumes, seeds, and tofu (just to name a few) are quick to prepare and are loaded with important nutrients like protein, fibre, iron and antioxidants! Here are a few delicious plant-based protein recipes to try. 

Vitamin C

Vitamin C – also known as L-ascorbic acid – is the powerhouse vitamin when it comes to immune health. It is an antioxidant that helps boost the immune system and synthesize collagen, which is the main structural protein found in our connective tissue. Unlike most animals, humans are unable to synthesize vitamin C in the body, which means it is an essential dietary component. This means we have to consume vitamin C through food (which is easy). Some great vitamin C-rich options include oranges, strawberries, kale, and bell peppers. Think of bright and colourful fruits and vegetables – these foods are often loaded with vitamin C and other immune-boosting phytonutrients like carotenoids. Aim for at least three different colours of fruits and veggies to help strengthen your immune system.

One of vitamin C’s jobs is to help improve the functioning of neutrophils (our white blood cells), which play a key role in fighting off germs. A deficiency in vitamin C in the body leads to a suppressed immune response and increased susceptibility to infections. While some studies have shown that neutrophil activity is best when vitamin C intakes are at least 250mg/day (in other words, vitamin C may help to prevent sickness), studies show that vitamin C is most powerful when taken during sickness, to reduce the duration and severity of a common cold. Furthermore, supplementing with vitamin C (when you have a cold) works best for those who start out with a mild deficiency.


To help protect your immune system, your body needs zinc! This mineral is often found in over-the-counter cold remedies because of its role in immune function and wound healing. Low levels of zinc can alter the immune system, as zinc is needed to develop and activate our T-lymphocytes, which play a central role in the immune system. If you’re looking for food sources of zinc, mushrooms are a great choice! They’re jam-packed with good nutrition and immune-boosting qualities (they also contain antioxidants and selenium!). Other sources of zinc include meat, fish, shellfish, legumes, dairy foods, nuts and seeds. 

Vitamin E

Vitamin E is a fat-soluble vitamin that is often found in foods containing fat, which is great, because fat is needed in order to absorb this vitamin! Food sources like nuts, seeds and avocados are all great snack ideas during cold and flu season as they contain multiple immune-boosting nutrients (hello protein and vitamin C!). Vitamin E is also a powerful antioxidant that works to protect the body from cellular damage by protecting cells from free radicals. This vitamin has also been shown to enhance the body’s immune response against certain infectious diseases. 

Vitamin D

Ever notice that cold and flu season seems to coincide with colder weather and reduced sunlight? Vitamin D deficiency is more likely to occur when our sun exposure is limited because we are unable to synthesize vitamin D in the body from sunlight! Our bodies utilize the sun’s UVB and UVA rays to convert a cholesterol precursor, known as 7-deyhdrocholesterol, into vitamin D. Without the sunshine, we are less likely to be making vitamin D, which means that we should be consuming vitamin-D rich foods and supplementing! To be honest, it is near impossible to consume enough vitamin D through food in order to meet daily requirements. So, my recommendation is to take 1000 IU (International Units) of vitamin D per day in the sunny summer months and 2000 IUs in the winter months.

Vitamin D has endless benefits – the list goes on and on. To name a few, vitamin D helps your body utilize calcium and phosphorus which is essential for maintaining strong bones and teeth, it has been linked to improved immune function, and a deficiency of vitamin D is linked to an increased susceptibility to infection, including respiratory infections (coughs and colds). All this said, it’s obvious that a daily supplement is necessary. I like Solves Strips Vitamin D – each strip contains 1000 IUs and they are SO easy to take (and taste great). 

Omega-3 Fatty Acids

Chances are you have heard about omega-3 fatty acids, or at least the power of “good” fats. If not – listen up. Gone are the days that thinking fat is bad. Fats, like the omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) play an important role in brain activity, heart health, and immune function. Omega-3 fatty acids also help to decrease inflammation and protect your lungs from respiratory infection. Although there are no government guidelines on the amount of EPA and DHA (the fish-based fatty acids), it is generally accepted that between 250-500 mg/day of DHA and EPA combined is a good starting point for adults. This equates to roughly 2-3 servings per week of fatty fish like salmon. If you’re not a fish eater, you can take a regulated fish-oil or algal oil omega-3 supplement. 


Beneficial bacteria, or probiotics, are another great way to support your immune system and to help maintain a healthy digestive tract. During cold and flu season a healthy gut is especially important because more than 70% of immune-related tissue is found in the gut

The gut is an amazing organ which not only helps digest and absorb nutrients but is also connected to your immunity. To help ward off sickness, make sure to consume probiotic-rich foods such as kefir, yogurt, tempeh, miso and kombucha! These naturally fermented foods will add a variety of beneficial bacteria to your gut which is just what it needs. Bonus – there has also been some promising research indicating that probiotics may also help shorten the duration and lessen the symptoms of colds! That’s a win in my books. 


About Sarah Remmer, RD

Sarah Remmer is a registered dietitian, author, writer/blogger, mom of 3, and founder of the Centre for Family Nutrition. She's passionate about teaching parents how to feed their families well (and stay nourished themselves!).


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