A practical, food-first guide to staying well through the colder months

Quick answer: To support your immune system naturally in winter, eat a varied, colourful, protein-rich diet, sleep seven to nine hours a night, move daily, manage stress and take vitamin D from October to March. Vitamin C, zinc, omega-3 and probiotics may offer extra support for some people.

Key points at a glance:

• Food first: aim for 30 different plant foods a week, with protein at every meal and two portions of fish weekly (one oily).
• Sleep, movement and stress management all measurably affect how well your immune system works.
• Vitamin D is the best-supported winter supplement in the UK, recommended from October to March.
• Supplements work best as an addition to a good diet, not a replacement for it.

Last reviewed: November 2026

As the days shorten and the temperature drops, many of us notice the same pattern: a cold here, a lingering cough there, and a general sense of running on empty. Winter does put extra demands on the body. We spend more time indoors, see less sunlight, tend to move less, and often reach for comfort food over fresh produce.

The good news is that your immune system responds well to consistent, simple support. There is no single “immune booster”, but a handful of daily habits, a nourishing diet and, where appropriate, a well-chosen supplement plan can make a real difference to how resilient you feel.

Here is where to start.

1.What are the best foods to support your immune system in winter?

Your immune cells need a steady supply of protein, vitamins, minerals and healthy fats to do their job. Rather than chasing superfoods, focus on covering the basics well.

Eat the rainbow, every day. Colourful vegetables and fruit provide vitamin C, carotenoids, flavonoids and other plant compounds that support immune function and help manage inflammation. Aim for at least five portions a day, and ideally closer to seven or eight, with a good variety of colours. Winter staples such as kale, cabbage, Brussels sprouts, beetroot, carrots, squash, citrus fruit and frozen berries all count.

Prioritise protein. Antibodies and immune cells are built from amino acids. Include a source of protein at each meal: eggs, fish, poultry, beans, lentils, tofu, nuts, seeds or quality dairy.

Get your zinc and selenium. Zinc is found in shellfish, red meat, pumpkin seeds, chickpeas and wholegrains. Selenium is found in Brazil nuts (just one or two a day is plenty), fish and eggs.

Include oily fish. Salmon, mackerel, sardines and herring provide omega-3 fats (EPA and DHA) and vitamin D. Aim for two portions of fish a week, one of them oily.

Add garlic, onions, ginger and turmeric. These kitchen staples have a long history of traditional use and contain compounds with antimicrobial and anti-inflammatory properties. A warming ginger and lemon tea or a garlic-rich broth is a lovely winter ritual, even if the evidence for them preventing illness is still modest.

Look after your gut. A large proportion of your immune tissue sits alongside your digestive tract. Support it with fibre-rich foods (oats, pulses, vegetables, fruit, wholegrains) and fermented foods such as live yoghurt, kefir, sauerkraut, kimchi and miso. Variety is key: aim for 30 different plant foods a week, including herbs, spices, nuts and seeds.

Go easy on the things that work against you. Frequent sugary snacks, heavy alcohol intake and a diet dominated by ultra-processed foods can all undermine immune function. You do not need perfection, simply more good choices than not.

Don’t forget a warm, nourishing soup. Homemade bone broth or a vegetable and lentil soup is hydrating, easy to digest and an easy way to pack in extra vegetables, particularly when your appetite is low.

2. How does sleep affect your immune system?

Sleep is when much of your immune repair and regulation takes place. Research consistently links short or poor-quality sleep with a higher risk of catching infections and a slower recovery.

To support better sleep this winter:

• Aim for seven to nine hours a night, with a consistent bedtime and wake time.
• Get outside in natural light early in the day, even on a grey morning, to help anchor your body clock.
• Dim lights and put away screens for the last hour before bed.
• Keep your bedroom cool, dark and quiet.
• Avoid caffeine after lunchtime and keep alcohol to a minimum, as it fragments sleep.

3. Does exercise help your immune system in winter?

Regular moderate exercise is associated with fewer respiratory infections and better immune surveillance. It does not have to be intense: a brisk daily walk, yoga, qigong, tai chi, swimming, cycling or strength training twice a week is plenty. Walking outdoors has the added benefit of daylight exposure.

One note of caution: if you are already feeling run down, or have a fever, rest instead. Pushing through intense training when your body is fighting something can prolong illness.

4. How does stress affect immunity, and what helps?

Long-term stress raises cortisol, which can dampen immune responses over time. You cannot remove all stress from life, but you can build in small, regular resets:

• Five minutes of slow breathing (try breathing in for four counts and out for six)
• A daily walk without your phone
• Time with friends and family, as social connection is itself protective for health
• Journalling, gentle stretching or a short meditation
• Protecting some genuine downtime in the week

5. Why is vitamin D so important in winter in the UK?

From roughly October to March, the sun in the UK is not strong enough for our skin to make vitamin D. Vitamin D plays an important role in immune regulation, and low levels are very common in winter. Eating vitamin D-containing foods (oily fish, eggs, fortified foods) helps, but food alone rarely gets us there, which is why supplementation is so widely recommended in the UK during winter.

6. What everyday habits reduce your risk of winter infections?

The basics still matter. Wash your hands regularly with soap and water, particularly before eating and after being in public spaces. Open windows for a few minutes each day to refresh indoor air, and stay home when you are unwell to protect others. Staying hydrated, with water and herbal teas, also helps keep your mucous membranes, your first line of defence, working well.

What are the best supplements for immune support in winter?

A food-first approach should always be the foundation, but certain supplements have reasonable evidence behind them and can be helpful in winter. The suggestions below are general guidance for healthy adults, not individual advice. Needs vary with age, diet, health conditions and medications, so it is best to consider testing and professional guidance where possible.

The foundations

Vitamin D3: 25 to 50 micrograms (1,000 to 2,000 IU) daily, October to March This is the most evidence-supported supplement for winter immune health in the UK. Official UK guidance recommends at least 10 micrograms daily through autumn and winter, and many practitioners use a higher maintenance dose, ideally guided by a blood test. Take it with a meal containing fat, and pair it with vitamin K2 if your practitioner recommends it. Do not exceed 100 micrograms a day without supervision.

Vitamin C: 500 to 1,000 mg daily Regular vitamin C does not stop most people catching colds, but studies suggest it may modestly shorten their duration and ease severity. Split the dose through the day or choose a buffered form if high doses upset your stomach.

Zinc: 10 to 15 mg daily Zinc is central to immune cell function. Some studies suggest zinc lozenges taken within 24 hours of the first cold symptoms may shorten a cold. Take with food to avoid nausea, and avoid long-term intakes above 25 mg a day from supplements, as high doses can deplete copper. Choose a well-absorbed form such as zinc citrate, bisglycinate or picolinate.

Worth considering

Omega-3 fish oil (or algae oil): 1,000 mg combined EPA and DHA daily Supports a balanced inflammatory response, and is particularly useful if you rarely eat oily fish. Vegetarians and vegans can choose an algae-based option.

A good-quality probiotic A multi-strain product containing Lactobacillus and Bifidobacterium strains may help reduce the frequency and duration of upper respiratory infections for some people. Choose a product with clearly labelled strains and look for studied ones.

Selenium: 50 to 100 micrograms daily Useful if you do not eat Brazil nuts, fish or eggs regularly. Do not combine with a high Brazil nut intake, and stay below the upper limit of 350 micrograms a day from all sources.

Seasonal extras (short term)

Elderberry extract Some small trials suggest elderberry may reduce the duration and severity of cold and flu symptoms when taken at the first sign of illness. It is a popular winter choice and can be taken as a syrup or capsule for a short period. The evidence is promising but limited.

Echinacea Results are mixed, but some people find it useful at the onset of a cold. Use short-term only.

A simple way to put it together

Supplement	Suggested daily amount	Best taken
Vitamin D3	25 to 50 mcg (1,000 to 2,000 IU)	With breakfast or lunch
Vitamin C	500 to 1,000 mg	Split across the day
Zinc	10 to 15 mg	With a meal
Omega-3 (EPA + DHA)	1,000 mg	With a meal
Probiotic	As per product	As directed
Selenium (if needed)	50 to 100 mcg	With a meal

Important cautions

• Supplements are not a substitute for a varied diet, good sleep and healthy habits.
• If you are pregnant or breastfeeding, have a medical condition, take regular medication (particularly blood thinners, immunosuppressants or thyroid medication), or are giving supplements to children, speak to a doctor, pharmacist or registered practitioner first.
• More is not better. Several of these nutrients have upper safe limits, so check labels and avoid doubling up across multiple products.
• Persistent or severe symptoms always warrant medical advice.

Your winter immune checklist

1. Eat a wide variety of colourful plants, plus protein at every meal
2. Include oily fish and fermented foods regularly
3. Prioritise seven to nine hours of sleep
4. Move daily, gently and outdoors where possible
5. Build in small stress resets
6. Supplement with vitamin D from October to March, and consider the rest of the stack according to your needs
7. Wash your hands, ventilate your home and rest when you are unwell

Small, steady habits matter far more than dramatic fixes. If you would like a personalised plan, including testing, tailored supplement protocols and a menu that fits your lifestyle, book a consultation and we can build a winter wellness strategy that suits you.

This article is for general information only and is not intended to diagnose, treat or replace individual medical advice.

Final thoughts…

Small, steady habits matter far more than dramatic fixes. If you would like a personalised plan, including testing, tailored supplement protocols and a menu that fits your lifestyle, book a consultation and we can build a winter wellness strategy that suits you.

This article is for general information only and is not intended to diagnose, treat or replace individual medical advice.