When the days get shorter and colder, I always focus on ways to boost my immune system and stay healthy through winter. Between less sunlight and lower vitamin D, more time indoors around germs (especially with little kids and school-aged kids!), it’s easy for a sniffle to turn into something bigger—and who has time for that? That’s why I turn to food as medicine, prioritizing nourishing, high-quality meals and targeted supplements to support my immune system all season long.

How To Boost Immune System: Why I Focus On Whole Foods & Supplements

Nutrient-dense foods—like colorful fruits and vegetables, high-quality proteins, broths, healthy fats, and fermented foods—provide the vitamins, minerals, and antioxidants your body needs to naturally defend itself. But even with a balanced diet, our modern lifestyles, stress, and seasonal changes can make it hard to get everything we need from food alone. That’s where supplements come in to fill the gaps and give your immune system the extra support it needs to thrive all winter long.

1. Nourish your body with immune-supporting food

Your immune system thrives on nutrients! Think colorful produce, whole foods, and healthy fats. You don’t need to overhaul your diet; just add more of these key players throughout your week.

Eat the rainbow:
Brightly colored fruits and veggies like bell peppers, citrus, kiwi, and broccolini are loaded with vitamin C, one of the best nutrients to boost your immune system. Add them to smoothies, salads, or grain bowls for an easy lift.

Try my Citrus Cold Flu Fighter this winter!

Don’t forget vitamin D:
Sunlight helps your body produce vitamin D, but during winter, that’s easier said than done. Include foods like wild salmon, sardines, egg yolks.

Add zinc-rich foods:
Zinc supports white blood cell function, which helps your immune system respond quickly. You’ll find it in pumpkin seeds, lentils, cashews, and seafood.

Warm, nourishing meals:
Soups, stews, and broths are perfect for the colder months — they hydrate, comfort, and pack a nutritional punch. Try a veggie-packed chicken soup or a beef stew for an easy weeknight dinner.

Fermented and fiber-rich foods:
A healthy gut = a strong immune system. Around 70% of your immune cells live in your gut, so include yogurt, kefir, sauerkraut, or kimchi in your meals. Pair that with plenty of fiber from fruits, veggies, and whole grains to feed your gut bacteria.

Nourishing & Gut-Friendly Soups

2. Create winter rituals that support immunity from the inside out

Beyond food, how you rest, move, and de-stress has a huge impact on your immune health. Think of these as small daily rituals that build resilience over time.

Prioritize sleep:
Sleep is the foundation of a strong immune system. Aim for 7–9 hours and keep a consistent bedtime routine. No screens 30 minutes before bed, dim lights, I always love mint tea or warm lemon and honey water after dinner.

One of the best health hacks during sleep is to have a humidifier going near your bed. This one from Canopy is my personal favorite and you can save 15% with my code ‘RGE’. I have one in all of our bedrooms!

Move your body daily:
Even light movement like a walk, yoga flow, or quick strength session boosts circulation and helps immune cells move throughout your body. Bonus: exercise is also a natural mood booster during darker months.

Get fresh air (even when it’s cold):
A quick outdoor walk in daylight is a great boost to your immune system. Take a 10-minute break after lunch to get a little natural light and reset your energy.

Stay hydrated:
Cold weather can dehydrate you just as easily as heat. Keep a water bottle handy, or sip on warm lemon water or herbal teas like ginger, turmeric, or echinacea to keep your throat and immune system happy. I also love sipping on electrolytes throughout the day. LMNT is my personal favorite brand!

3. Supplement support

While food and lifestyle are your foundation, supplements can help fill in the gaps — especially during the winter months. These are the ones I personally love (and take consistently), you can find my full list of supplements in this blog post. You can also shop all my recommended brands on my Amazon storefront.

• Multivitamins (code RACHAEL20)
• vitamin D3 + K2 spray: Essential in winter when sunlight is limited. Supports both immune and bone health.
• Vitamin C: Antioxidant that helps immune cells function effectively.
• Cymbiotika Zinc: Aids in immune response and wound healing.
• Synbiotic+: Support gut health, which directly influences immune function.
• Omega 3 + D3: Help regulate inflammation and support overall wellness.
• Magnesium, Magnesium L-Threonate: Supports relaxation and sleep, indirectly helping your immune system recharge.