Top Winter Superfoods to Boost Immunity & Energy Naturally
As the days get shorter and the weather turns colder, our bodies work harder to stay warm, ward off infections, and keep energy levels steady. This is the perfect time to focus on seasonal superfoods, containing ingredients that naturally support your immune system, metabolism, and mood through the winter months.
In functional nutrition, we look at food as information, and the signals you send your body with every bite. By choosing nutrient-dense, seasonal foods, you can strengthen your defences and maintain steady energy all winter long.
Mushrooms — Nature’s Vitamin D Booster
Mushrooms are one of the few plant foods that naturally provide vitamin D a nutrient that becomes even more important during the darker months when we get less sunlight. Vitamin D helps your immune system work efficiently, supporting your body’s ability to fight off infections. It also plays a key role in mood regulation, helping to support serotonin production and prevent that “winter slump” feeling.
Here’s a simple trick: mushrooms contain a compound called ergosterol, which turns into vitamin D₂ when exposed to sunlight. If you leave your mushrooms on a sunny windowsill for about 30 minutes before cooking, you can naturally increase their vitamin D content no supplements required!
Mushrooms also contain beta-glucans, a type of soluble fibre that helps your immune system stay balanced. Rather than overstimulating it, beta-glucans help your body respond appropriately to infections while keeping inflammation under control. They may also support the activity of your white blood cells your body’s first line of defence against illness.
Try this: sauté chestnut or shiitake mushrooms with garlic, thyme, and olive oil, or stir them into soups and omelettes for an easy immune-supporting boost.
Sweet Potatoes — Steady Energy and Antioxidant Power
Sweet potatoes are a brilliant source of slow-releasing carbohydrates, which means they help keep your blood sugar balanced and your energy levels steady throughout the day, no more mid-afternoon crashes or sugar cravings.
Their bright orange colour comes from beta-carotene, a powerful antioxidant that your body converts into vitamin A. This vitamin plays a vital role in keeping your skin healthy, your vision sharp, and your immune system strong, particularly important in the colder months when your body’s defences are under more pressure.
Sweet potatoes also provide fibre to support gut health and potassium to help regulate blood pressure and fluid balance, making them a nourishing, all-round winter staple.
Try this: Roast sweet potato wedges with olive oil, smoked paprika, and sea salt for a warming, nutrient-rich side dish. Or mash them with coconut milk for a creamy, comforting alternative to traditional mash.
Carrots and Root Vegetables — Grounding and Nourishing
Carrots, parsnips, and beetroot are true winter heroes. These root vegetables grow underground, drawing up minerals from the soil, which makes them especially rich in nutrients like potassium, magnesium, and antioxidants that support your energy, circulation, and recovery.
Their natural sweetness makes them a great way to satisfy cravings without reaching for sugary snacks, while still keeping blood sugar levels steady. They’re also a wonderful source of fibre, which feeds the beneficial bacteria in your gut; an important part of maintaining a strong immune system.
Each root vegetable brings its own unique benefits:
Carrots are rich in beta-carotene, supporting healthy skin and immune defence.
Beetroot helps improve blood flow and oxygen delivery to your muscles and brain.
Parsnips provide slow-release energy and are soothing on the digestive system.
Try this: Roast a mix of carrots, parsnips, and beetroot with olive oil, rosemary, and a sprinkle of sea salt. Or blend them into a hearty soup with red lentils for a filling, nutrient-packed winter meal.
Garlic and Onions — Your Natural Cold Fighters
Garlic and onions are two of the most powerful foods you can include in your winter diet. They both contain sulphur compounds (like allicin) and antioxidants that help your body fight off viruses and bacteria, perfect for supporting your immune system through the colder months.
They’re also rich in prebiotics, which feed the beneficial bacteria in your gut. Since around 70% of your immune system lives in your gut, keeping your microbiome healthy is one of the best ways to strengthen your natural defences.
Garlic and onions even support liver detoxification, helping your body process hormones, toxins, and everyday pollutants more efficiently. This keeps inflammation low and energy levels more stable.
Here’s a simple tip: when using fresh garlic, crush or chop it and let it sit for about 10 minutes before cooking. This activates allicin, the compound responsible for its immune-boosting properties.
Try this: Add sautéed onions and garlic as a base for soups, stews, or sauces, or roast a whole bulb of garlic and spread the soft, caramelised cloves onto sourdough toast for a natural immune boost.
Citrus Fruits — Vitamin C for Immune Defence.
When you think of winter superfoods, citrus fruits like oranges, clementines, grapefruits, and lemons should be right at the top of the list. They’re bursting with vitamin C, one of the most important nutrients for keeping your immune system strong and helping your body fight off colds and infections.
Vitamin C also supports collagen production, which keeps your skin healthy and resilient during the cold, dry months. It acts as a powerful antioxidant, protecting your cells from damage and helping to reduce inflammation.
Citrus fruits are also rich in flavonoids; plant compounds that work alongside vitamin C to boost your body’s antioxidant defences and support healthy blood vessels and circulation.
Their natural acidity can help stimulate digestion, which often slows down in winter when we eat heavier foods. Starting your morning with something citrus-based can gently wake up your digestive system and boost hydration.
Try this: Begin the day with warm water, lemon, and a pinch of sea salt to rehydrate and support digestion. Or add orange segments to a salad with rocket, avocado, and toasted seeds for a light yet energising winter meal.
Nuts and Seeds — Small but Mighty Energy Boosters
Nuts and seeds may be tiny, but they’re packed with powerful nutrients that help you stay energised, balanced, and resilient through the winter months. They’re a great source of healthy fats, plant-based protein, and key minerals like zinc, magnesium, and selenium, all essential for strong immunity and steady energy.
Zinc supports the production of white blood cells that help fight off infections.
Magnesium helps calm the nervous system and supports good-quality sleep.
Selenium, found in Brazil nuts, is a potent antioxidant that helps protect your cells and regulate thyroid function; important for maintaining energy and metabolism.
The healthy fats found in nuts and seeds also support hormone balance, brain health, and skin hydration, all things that can take a hit during cold weather.
Because they’re rich in both protein and fibre, nuts and seeds also help keep blood sugar levels stable, reducing cravings and preventing energy dips between meals.
👉 Try this: Sprinkle mixed seeds (like pumpkin, sunflower, and flax) on porridge or yoghurt, snack on a handful of almonds or walnuts, or add crushed nuts to roasted vegetables for extra crunch and nourishment.
Leafy Greens — Don’t Skip the Greens in Winter
Even in winter, leafy greens like kale, spinach, cavolo nero, and Swiss chard are nutritional powerhouses that should not be overlooked. They are packed with vitamins, minerals, and antioxidants that support energy, immunity, and overall wellbeing.
Iron helps transport oxygen around your body, keeping energy levels steady and preventing fatigue.
Folate (vitamin B9) is important for cell health, detoxification, and mood regulation.
Vitamin C in leafy greens works alongside iron to help your body absorb it more efficiently and also boosts immune function.
Leafy greens are also high in fibre, which nourishes your gut bacteria. A healthy gut is crucial for immune support, balanced hormones, and efficient digestion, all of which can be more challenging in the colder months.
Even though salads may feel less appealing in winter, there are many ways to enjoy greens cooked or lightly wilted:
Sauté with garlic and olive oil as a side dish.
Stir into soups, stews, or casseroles.
Blend into smoothies for a nutrient-packed start to your day.
By including leafy greens in your meals, you’re supporting your body’s energy, immunity, and overall resilience during winter, making them a key part of seasonal eating.
Try this: wilt kale into soups, toss with roasted vegetables, or sauté with garlic and olive oil for a quick side.
Nourish, Don’t Restrict
Winter is not the time for rigid diets or restriction. Your body needs warmth, nourishment, and steady blood sugar to thrive. Focus on balance, combining slow-release carbohydrates, quality protein, healthy fats, and plenty of colourful plants in each meal.
When you eat seasonally and in tune with your body’s needs, you naturally support your immune system, boost your energy, and feel more grounded.
💚 Need Personalised Guidance?
If you’d like to understand how your nutrient intake, stress levels, or hormone balance are impacting your energy this winter, my Nutrition Blueprint and Personalised Nutrition packages can help.
Together, we’ll create a plan that’s tailored to your body, lifestyle, and goals, so you can feel your best all season long.