Supporting Your Immune System Through Seasonal Changes
As the warmth of autumn fades and the cooler air begins to settle in, many of us instinctively adjust our habits —swapping salads for soups, bringing out heavier layers and spending more time indoors. However, as our surroundings shift, so too do the needs of our bodies particularly our immune system.
Winter has long been associated with a rise in seasonal illnesses, from the common cold to influenza and more recently, heightened awareness of respiratory infections in general. The question isn’t just how to “boost” immunity but how to support it in a sustainable and informed way.
Understanding Immune Vulnerability in Winter
During colder months, we tend to spend more time in close proximity to others, indoors and with less ventilation. Ideal conditions for viruses to spread. At the same time, our exposure to sunlight and therefore Vitamin D synthesis declines, which can reduce immune efficiency. Even our sleep and circadian rhythms may be disrupted as daylight hours shorten, impacting the body’s ability to repair and regulate inflammation.
Additionally, stress levels often rise during the winter months. Busy work periods, end-of financial year obligations and even the effects of seasonal affective disorder (SAD) can take a toll on our mental wellbeing, which in turn influences immune resilience. When stress hormones such as cortisol remain elevated for extended periods, immune responses can become suppressed or dysregulated.
A Proactive and Personalised Approach
Rather than taking a reactive stance by responding only once illness strikes winter invites a more thoughtful and preventative approach. Supporting the immune system isn’t about quick fixes, it’s about setting a strong foundation.
Key areas worth reflecting on as winter begins include:
Nutrient Replenishment: Immune cells require a wide range of micronutrients to function optimally. Vitamin C, Zinc, Selenium, and Vitamin D are especially important during the colder months. While whole foods remain the best source of nutrients, supplementation may be helpful particularly, with Vitamin D which many Australians are deficient in during winter.
Movement and Rest: Gentle exercise, even brisk walks outdoors help keep circulation and immune surveillance active. Equally important is sleep, which is when the body performs much of its immune system regulation and tissue repair. Ensuring 7–9 hours of high-quality sleep can make a measurable difference in winter wellness. For those needing additional support, certain amino acids may be beneficial. Compounds like Gamma-Aminobutyric Acid (GABA), L-Theanine, and 5-Hydroxytryptophan (5-HTP) have been shown to enhance sleep quality and support a healthy stress response (Schuler, 2025). These can be useful aides when managing winter-related fatigue or disrupted sleep cycles
Targeted Herbal Support: Herbal medicine offers a range of options with immune-modulating properties. Echinacea, astragalus, elderberry, and medicinal mushrooms like reishi and shiitake are often used to support immune defence and recovery. Healthcare professionals can guide patients toward safe, evidence-based use of these options, particularly where underlying conditions exist.
Stress and Emotional Health: While often overlooked, mental and emotional resilience are key components of immune function. Mindfulness practices, social connection and even time in nature when possible, can support a healthy stress response.
Rather than viewing immune support as a seasonal scramble, we can embrace it as part of a consistent, holistic approach to wellness.
Schuler, C. (n.d.). 3 Amino Acids for Better Sleep and Relaxation Support. Today's Practitioner. Available at: https://todayspractitioner.com/stress/3-amino-acids-for-better-sleep-and-relaxation-support/ [Accessed 9th May 2025].