Essential immune support for winter
As the cooler months roll in, so too does the wave of sniffles, sore throats, and lingering coughs.
Below are my top immune-supporting strategies, using food as medicine, targeted nutrients, and natural compounds to help your body stay strong and recover faster when illness strikes.
Nutrients:
Zinc - essential for immune cell function. Zinc is needed for the development and activity of key immune cells like neutrophils and macrophages. It is a strong anti-viral and supports gut health (where most of the immune system is found).
Food sources: zinc is best absorbed from animal foods such as beef, lamb or oysters. It is found in lentils, nuts and seeds but due to plant compounds like phytates, we do not absorb zinc as well from plant foods (soaking these foods does help if possible)
Pro-tip: the best forms of zinc are zinc glycinate, zinc citrate or zinc picolinate.
Vitamin C - boosts white blood cell (our immune cells) activity and production to help your body detect and fight off pathogens faster. Vitamin C can reduce the duration and severity of symptoms when taken at higher doses during early stages of illness
Best food sources: citrus fruits, kiwi, strawberries, capsicum, broccoli, parsley, papaya, and guava
Pro tip: we can only absorb 1000mg of vitamin C each hour, so you can dose 1000mg a few times a day when sick to really boost your immune system.
Vitamin D - our immune cells actually have vitamin D receptors, meaning they depend on vitamin D to function properly. Low levels of vitamin D are linked to higher rates of infections and poor recovery from illness.
Tip: sun is the most efficient source, we need about 15–20 minutes of midday sun on our skin (without sunscreen or much clothing) a few times a week (depending on skin tone and location) to maintain adequate vitamin D levels (is anyone these days doing this - not really!). It is no wonder why vitamin D deficiency is extremely common, even in countries like Australia. I often recommend my clients to take a vitamin D supplement over winter due to this factor.
Selenium - is a lesser-known but crucial nutrient for immune function, especially in viral defence and antioxidant support. It enhances white blood cell activity - helping the body detect and destroy viruses and bacteria.
Tip: 2–3 Brazil nuts a day provide your daily selenium needs! It is best to source good quality, organic Brazil nuts that come from better soil quality for higher selenium levels.
Iron - is essential for a robust and responsive immune system. Both low and high levels of iron can impact immune function, making balance key. It supports white blood cell function, it’s required for the development and activity of lymphocytes (especially T-cells), which are essential for defending the body against viruses and bacteria.
Tip: we best absorb iron from animal sources (haem iron) such as red meat, lamb, liver and eggs. Plant based sources of iron (non-haem iron) include lentils, spinach, pumpkin seeds, quinoa, tofu - they are best absorbed when paired with vitamin C.
Vitamin A - has a foundational role in maintaining immune barriers and supporting immune cell function. It helps maintain the integrity of mucous membranes (the linings of your lungs, gut, throat, and reproductive tract) - which are your first line of defence against viruses and bacteria.
Tip: like iron, we best absorb vitamin A from animal sources (in the retinol form) such as in liver, egg yolks, full-fat dairy, cod liver oil. Plant foods contain beta-carotene which is the precursor to retinol, and many of us do not convert beta-carotene to retinol well due genetics and other factors. Plant foods with beta-carotene include - carrots, sweet potato, pumpkin, spinach, kale, capsicum.
Food & herbal medicine:
Mushrooms - are some of the most powerful natural immune modulators available. The beta-glucans found in mushrooms like Shiitake, Reishi and Turkey tail strengthen, balance, and train the immune system. They have anti-bacterial and anti-viral properties. Best taken in powder or tincture form.
Propolis - modulates and boosts the immune system, it has anti-bacterial, anti-viral and anti-fungal properties. It is great as a spray or in a lozenge for a sore throat.
Echinacea - helps stimulate white blood cell production, particularly macrophages and natural killer cells, which are your body’s first line of defence against pathogens. It boosts immunity, is naturally anti-viral and anti-bacterial and has been shown in research to reduce duration and intensity of cold symptoms.
Elderberry - has immune modulating actions and is a strong anti-viral. It also tastes delicious and can be made into an elderberry syrup for immune support.
Astragalus - helps stimulate the production of white blood cells, especially T-cells and macrophages, which are essential for identifying and destroying pathogens. It’s considered an immune builder - supporting long-term resilience and defence. It also is an adaptogen like Reishi so it supports stress resilience (which in its own way supports the immune system as stress directly downregulates our immune system and makes us more susceptible to illness)
Lifestyle habits that directly down regulate the immune system - i.e. making it less effective at fightings bugs:
Poor sleep - even one night of poor sleep can reduce your immune defence the next day! Poor sleep causes less natural killer cell activity, which impairs your ability to fight off viruses.
High stress = high cortisol = suppressed immunity. Cortisol suppresses immune cell activity and prolonged stress also increases inflammation.
Nutrition - a diet high in sugar, refined carbohydrates, and ultra-processed foods affects immunity on multiple levels:
Elevated blood sugar temporarily impairs white blood cell function for hours after eating.
Ultra-processed foods promote chronic inflammation, oxidative stress, and gut dysbiosis - all of which suppress immune resilience.
Low intake of immune-supportive nutrients (like zinc, vitamin C, selenium, and fibre) starves your immune system of what it needs to function.
The good news - these are all modifiable factors. Even small changes like getting more sleep, managing stress through breathwork, herbal adaptogens or nature time, and eating whole, nutrient-dense foods can significantly improve your immune resilience.