Winter Immunity Guide: How to Boost Your Immune System with the Right Vitamins and Healthy Habits
Discover how you can support your immune system in winter with science-supported habits, immune-supporting foods and targeted supplementation.*
Winter has a way of testing even the strongest routines. Colder mornings make training harder to get started, recovery can feel slower, and time spent indoors can increase exposure to everyday stressors.
The good news is, your immune system is built to adapt.
Whether you’re training hard, staying active for your wellbeing, or juggling a busy family life, this guide explores why winter places extra demands on your immune system — and how you can support your health with science-supported habits and the right supplementation.
You've probably heard a dozen theories about why colds and flu spike when temperatures drop. Your grandmother might've warned you about going outside with wet hair. Your coworker swears it's because everyone's stuck inside together.
But the truth is, cold weather itself doesn't make you sick - viruses do. Winter creates the perfect conditions for those viruses to thrive and spread more easily. Here's how it works.
More Time Indoors Means More Exposure
As temperatures drop, we spend more time indoors with windows closed and limited ventilation. Shared indoor spaces, such as schools, offices, homes and gyms, become enclosed spaces where respiratory droplets can linger longer, increasing transmission risk.
Dry air weakens your natural defenses
Your nose and throat have a built-in defense system: mucus. It sounds gross, but that sticky layer traps viruses before they can take hold. Winter air, especially heated indoor air, dries out your nasal passages and makes that protective barrier less effective.
Research shows that when relative humidity drops below 40%, the influenza virus survives longer in the air and your body's ability to clear it out may be reduced.
Less sunlight = less vitamin D
Have you ever heard the theory that the sun kills germs? Vitamin D plays a crucial role in immune function and is produced naturally in your body when your skin is exposed to sunlight. During winter, shorter days and weaker UV rays can mean you’re not producing as much vitamin D.
Studies have found that people with low vitamin D levels are more susceptible to respiratory infections. One meta-analysis of 25 trials involving over 11,000 participants found that vitamin D supplementation reduced the risk of acute respiratory infections, especially in people who were deficient.*
Put all these factors together, and winter becomes a season where your immune system has to work harder than usual.
You can't control the weather or eliminate every virus from your environment. But you can absolutely strengthen your defenses and reduce your exposure through consistent, healthy habits.
Wash your hands
Handwashing remains one of the most effective ways to reduce the spread of everyday germs, and research shows that regular handwashing can help reduce respiratory infections by up to 21%.*
Use soap and water for at least 20 seconds (singing the "Happy Birthday" song twice is an easy way to time it), and make sure to hit all the spots: between your fingers, under your nails, and the backs of your hands. Carrying hand sanitiser is a great backup for when you’re on the go or travelling. Make sure to look for one with at least 60% alcohol.
Move your body regularly
Moderate exercise supports immune function by promoting good circulation and helping immune cells move through your body more efficiently.* You don't need to crush high-intensity workouts every day, though. An easy 30-minute walk, a yoga session, or a moderate strength training routine does the job.
Prioritize quality sleep
While you’re sleeping, your immune system does much of its repair work. Research shows that people who get over 7 hours of sleep per night are supporting their immune system. Aim to get 7–9 hours of sleep nightly.
For those looking to improve sleep quality, our guide to magnesium and melatonin breaks down how these supplements can help support better sleep.*
Manage stress levels
We all know that stress is one of the worst things for our immune system. Research suggests chronic stress can lead to sustained cortisol release, which may suppress immune function over time.*
Simple practices like breathwork, meditation, or spending time outdoors can make a meaningful difference, even when done briefly and consistently. Even short daily practices make a difference, with this study finding that mindfulness meditation lowered cortisol levels in the blood.
If you’re feeling burnt out, this guide offers practical strategies to help you reduce stress and support your everyday wellbeing.*
Eat Foods to Support Immune System Function
What you eat plays an important role in overall health, including how well your immune system functions day-to-day. A varied, whole-food-based diet helps provide the vitamins, minerals and naturally occurring compounds your body relies on to carry out its normal processes.
You don’t have to pack your diet with superfoods like kale and acai berries, though, just aim for consistency and variety across your meals, including:
A wide range of fruits and vegetables, especially colourful options
Lean sources of protein such as poultry, fish, red meat and eggs
Plant-based protein alternatives like beans, lentils, chickpeas, tofu and edamame
Healthy fats from foods like olive oil, nuts and seeds
Fermented foods like yoghurt, sauerkraut or kimchi
Stay hydrated
Hydration is a key part of supporting overall health, but in winter, it’s common to drink less water without realizing it.
As a general guide, adults are encouraged to consume around 2–2.5 liters of fluids per day, while children may need approximately 1–2 litres depending on age. These amounts include fluids from water, other beverages and foods, and individual needs can vary.*
For those who find it challenging to meet their daily water intake, Sports Research Hydrate Electrolytes Jar provides a simple way to support hydration as part of a daily routine, without added sugar.*
Even with balanced meals and healthy habits, it’s not always easy to meet nutritional needs year-round. The right supplementation can help support daily nutrient intake during winter.*
Multivitamin
During winter, training schedules, meal patterns and daily routines often change, which can make nutritional consistency harder to maintain.* Some people choose to include a high-quality multivitamin during this time to support everyday nutritional intake alongside a balanced diet.*
Our Advanced Multivitamin is designed to support your routine with a broad range of essential nutrients involved in normal daily body functions, including:
B vitamins, which play a role in cellular energy and metabolic processes*
Vitamin C, a well-known antioxidant that supports immune system health*
Magnesium, involved in muscle and nerve function*
CoQ10, which supports normal energy production within the body*
Vitamin D3
Depending on where you are in the world, most people generally get less sun exposure than needed in winter. Vitamin D, also known as the “sunshine vitamin,” is essential for supporting your body's needs for stronger, healthier bones and immune function. *
Our easy-to-swallow Vitamin D3 softgels are the most convenient way to add some D3 to your day.*
For those following a plant-based lifestyle, we also created a Vegan Vitamin D3, providing the same form of vitamin D in a vegan-friendly format.
Oil of Oregano
Oil of Oregano has been used for centuries as part of traditional wellness practices. Oil of Oregano is often paired with black cumin seed oil because both ingredients provide naturally occurring antioxidants from different plant sources.*
Together, these oils offer a complementary blend of plant-based compounds that can be included as part of a balanced approach to immune system support.*
How do you know if your immune system needs support?
Some people notice signs such as ongoing fatigue, slower recovery, poor sleep or getting sick more often during winter. These patterns can indicate that the immune system is under increased demand and may benefit from additional support.*
How can I support my immune system naturally in winter?
Supporting your immune system naturally in winter often starts with consistent daily habits. This includes staying active with regular movement, prioritising quality sleep, managing stress, eating a varied, whole-food-based diet, staying hydrated and practising good hygiene. Some people also choose to include supplements as part of their routine to support nutritional intake during winter.*
Why do we get sick more in winter?
Winter often brings more time spent indoors, reduced ventilation, drier air and less sunlight. Together, these factors can increase exposure to everyday germs and place extra demands on the immune system, making it easier for illnesses to circulate during colder months.
How long does it take to support immune health?
There’s no set timeline for supporting immune health, as it depends on individual routines, lifestyle habits and consistency. Focusing on supportive habits like sleep, nutrition, movement and stress management over time is generally more important than short-term changes.*
What vitamins are commonly used for immune support?
Vitamins commonly included in immune-support routines include vitamin D, vitamin C and B vitamins, as well as vitamin K, which is often paired with vitamin D.* These nutrients are involved in normal immune system function and everyday body processes, and are typically consumed through a balanced diet or included as part of seasonal supplementation routines.*
Explore our range of Wellness and Immunity supplements.
The Bottom Line
We’ve covered why winter can place extra demands on your immune system, how to recognize when your body may need support, and the everyday habits that can help you support your immune system during winter.*
Here’s a quick recap:
Stay active with regular, moderate movement
Practice healthy hygiene with handwashing
Prioritize quality sleep and a consistent routine
Manage everyday stress where possible
Eating a varied, whole-food-based diet
Stay hydrated with water and electrolytes
Pair these healthy habits with the right supplements, and these small daily habits add up to a more supported immune system to help you manage the winter months.*
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
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