Boost your immunity and keep well this winter!

Here are some tips to help boost your immune system during the winter months when colds and flu are more prevalent. 


1. Firstly, try to get as many nutrients, vitamins and minerals from your food as you can.

Supplements have their place, but you need to be taking the right type and dose based on you and your needs. More isn’t always better. And there’s no great value in swallowing down heaps of supplements when you are already sick. 

As always, plenty of colourful veggies, as well as some fruit, lean proteins, and whole grains are great to include in your meals.  


Key things to include, or increase, in your diet if you can:  



  • Your body doesn’t store vitamin C, so daily top ups are required! 

  • Vitamin C found in many foods, especially fruits and vegetables. Well known as an antioxidant and to support skin health and immune function. 

  • Sources include: citrus fruits, kiwifruit, pineapple, watermelon, broccoli, brussels sprouts, cauliflower, green and red peppers, leafy greens, potato  

  • How much vitamin C is in that winter food? 

  • A Guide to vitamin C supplements 



  • Iron is vital for a healthy immune system. It is estimated 1 in 14 women in NZ are low in iron and 8/10 toddlers are short on iron too. 

  • If you are vegetarian or vegan, you are at higher risk of not getting enough iron so that’s something to be mindful of. If you are tired all the time and/or get sick a lot, it is well worth getting your iron tested. 

  • Vitamin C enhances the absorption of non-haem iron (the type found in plant foods), so look to have foods rich in Vitamin C (see above) when you have plant sources of iron. More on that here. And keep your tea drinking away from your meals as this can compromise the absorption of iron.  

  • Sources include: shellfish, red meat, liver, spinach, legumes, pumpkin seeds, quinoa, broccoli, tofu and dark chocolate 



  • Another mineral that is super important for a healthy immune system that isn’t stored in the body so needs to be replaced daily. Many kiwis don’t get enough, particularly men!  

  • Sources include: oysters, red meat, chicken, dairy, grainy bread, eggs, cashew nuts, pumpkin seeds and chickpeas 

  • A guide to zinc   



  • Vitamin D supports our immune system, bone health and mental wellbeing. It really is true that the sun makes us feel good!  

  • Many of us spend most of our day indoors and get very little sun exposure. Your body is able to make Vitamin D when you expose your skin to light, so be sure to GET OUTSIDE even over the colder months and expose your more of your skin if you can! Roll up your sleeves. 

  • Food sources include: oily fish (including salmon, mackerel, and sardines), egg yolks, red meat and liver. Vitamin D is added to some foods too, including breakfast cereals and plant milks. Avocados, nuts, seeds, full fat dairy products, and eggs are nutritious sources of fat that help boost your vitamin D absorption. But sunlight is your best source! 



  • Vitamin A plays an anti-inflammatory role in enhancing immune function. 

  • There are two forms of Vitamin A found in food: 

  • Preformed Vitamin A: egg yolks, liver, cod liver oil, salmon and cheese 

  • Proformed Vitamin A: orange kumara, pumpkin, carrots, kale, spinach and cabbage 


2. Good quality sleep is super important to keep your immune system strong! 

Sleep is just as important as putting the right nutrients into your body. Research has shown that lack of sleep and stress (which go hand in hand) can impair our immune system making it even harder to fight off those winter bugs. 

One major culprit of the sleep deprivation epidemic is our unhealthy obsession with technology. There is a growing body of research around sleep and its effect on our internal body clock (circadian rhythm), delaying melatonin hormone production and raising cortisol levels. Poor sleep also causes low blood sugar levels, making you more hungry and likely to crave sweet foods throughout the day. Like a hangover minus the alcohol! 


Try these simple tips to promote a healthy night’s sleep: 

  • Try to avoid technology at least an hour before bed, particularly phones, laptops and tablets, if you can’t at least dim the screens and set to night mode 

  • Pass up stimulants after lunch - caffeine, alcohol, sugary foods 

  • Ensure you have a dark room - choose black out curtains to encourage melatonin production 

  • Wind down before bed - pick up a book, take a bath, enjoy a cup of relaxing herbal tea like chamomile  


3. Manage stress levels 

Excess cortisol (stress hormone) can suppress our immune system. Stress, combined with inadequate nutrients, lack of exercise and sleep may increase your vulnerability to catching the common cold and flu. 


Be aware of your stress triggers and have coping strategies in mind ahead of time to reduce the impact, here are some suggestions: 

  • Be informed not consumed by managing the amount of bad news you tune into and focus on. Look for the good in the world and for what is going well your life, and choose to see the best in others 

  • Take microbreaks to allow your brain time to process all the constant input  

  • Avoid using your phone at all opportunities (e.g. when you are in the lift or standing in a queue) 

  • Difficult days and experiencing challenging emotions are a normal part of life - avoid self-judgement and critical self-talk when things don’t go to plan 

  • Be mindful of who you spend your time with and focus on people who give you good energy 


Try these simple self-care, stress reducing tips to help lower stress hormones: 

  • diaphragm breathing 

  • meditation or mindfulness 

  • being in nature 

  • reading 

  • yoga or gentle stretching  


This is a great quote to keep in mind: 

“One day I decided that hurry and stress were no longer going to be part of my life. Stress is self-created; I decided to stop manufacturing it. We can choose an internal calm and joy even amid the chaos” - Brendon Burchard 


A few extra tips: keep hydrated, remain active and move regularly, wash your hands, limit alcohol and avoid smoking, and stay connected to people who make you feel happy! 


If you would like one-on-one personalised nutrition advice to suit you and your lifestyle, please get in touch or make a booking with one of the team at Mission Nutrition today! We’d love to help. 
If you have health insurance, don’t forget to check your policy too. You might be able to claim back the cost of a consultation. 


Take care this winter! 




Published By

Claire Turnbull



Mission Nutrition Dietitians and Nutritionists © 2024.     Terms and Conditions