the key nutrients you should eat to stay well this winter.

The Key Nutrients You Should Eat to Stay Well This Winter

Your immune system never truly switches off. It works quietly in the background, protecting you from seasonal stress, changing temperatures, and everyday exposures. How well it performs depends not just on what you eat, but on how effectively your body can absorb and use those nutrients.

Research increasingly shows that nutrient absorption and immune strength are closely connected. When your gut is healthy, it absorbs vitamins, minerals, and antioxidants more efficiently, fuelling your immune cells and keeping inflammation in check. When that balance falters, even the most nutrient-rich diet may not deliver the benefits you expect.

Why Gut Health Matters for Nutrient Absorption

Your gut lining is more than just a digestive surface. It is your body’s gateway to nourishment. Tiny, hair-like projections called villi and microvilli line the small intestine, allowing nutrients to pass into the bloodstream. A healthy gut barrier and a diverse microbiome make this process far more efficient. Beneficial bacteria also help release vitamins such as B12, K, and folate, and improve the absorption of minerals like iron, calcium, and magnesium.

When the gut becomes inflamed or imbalanced, nutrient uptake can decline. Over time, this may leave you feeling fatigued or run down, a sign that your immune system is not receiving the support it needs. Supporting your gut health through balanced eating, fibre, and fermented foods ensures the nutrients you consume are fully used by your body. Including a synbiotic supplement, which combines both probiotics and prebiotics, can also be a helpful way to maintain balance in your gut microbiome. Taken alongside a diet rich in fruits and vegetables, it can provide extra support for a healthy digestive environment and better nutrient absorption.

Nutrients That Keep Your Immune System Strong

Below are the key nutrients that act as the building blocks of immune function and how you can easily include them in your diet.

Vitamin D
Vitamin D helps immune cells recognise and respond to pathogens effectively. Low levels have been linked to a higher risk of infection, especially in winter when sunlight exposure is limited. Studies suggest that oily fish such as salmon, mackerel, and sardines can provide around 40 to 60% of your daily requirement in one serving, depending on the species. Fortified dairy and eggs are also excellent everyday sources.

Vitamin C
Vitamin C protects immune cells from oxidative stress and supports the production of antibodies. Research shows that just one medium orange or a cup of chopped bell pepper provides more than 100% of your daily intake. Foods such as kiwifruit, strawberries, and broccoli are also potent sources that help your immune cells stay healthy and responsive.

Vitamin A
Vitamin A supports mucosal immunity, the body’s first line of defence in the lungs and gut. It helps maintain the health of epithelial cells, which act as a barrier against pathogens. A small serving of cooked carrots or sweet potato can meet up to 80% of the recommended daily intake, while dark leafy greens such as spinach and kale add valuable beta-carotene, the plant form of vitamin A.

Zinc
Zinc plays a central role in immune cell development and communication. It also regulates inflammation by influencing cytokine production, the chemical signals immune cells use to coordinate their response. Shellfish, particularly oysters, are among the richest natural sources, while plant-based eaters can turn to lentils, beans, and pumpkin seeds for steady intake.

Selenium
Selenium supports antioxidant enzymes that protect cells from oxidative stress during infection. It also assists the body’s production of antibodies. Just one Brazil nut can provide your full daily requirement, while seafood, eggs, and mushrooms offer additional sources.

Omega-3 Fatty Acids
Omega-3s, particularly EPA and DHA, are anti-inflammatory fats that influence how immune cells communicate and move throughout the body. Regular intake from fatty fish such as salmon and trout has been shown to reduce inflammatory markers and improve immune resilience. For plant-based options, chia seeds, flaxseeds, and walnuts are rich in ALA, which the body can convert in smaller amounts to the active forms.

A Nutrient-Rich Pattern for Long-Term Wellness

The Mediterranean diet is one of the best examples of how to eat for both immune and gut health. It is built on olive oil, colourful vegetables, beans, nuts, and fish, a combination that reduces inflammation and nourishes beneficial bacteria. Its wealth of antioxidants, including vitamin C from citrus fruits and peppers, vitamin E from olive oil and almonds, beta-carotene from carrots and greens, lycopene from tomatoes, and polyphenols from herbs and berries, helps protect immune cells from oxidative stress and supports natural repair processes. Adherence to the Mediterranean pattern enhances immune resilience and reduces chronic inflammation over time.

References

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