How to Support Your Immune System in Autumn: A Practical Guide

KEY POINTS

• Start vitamin D in September rather than waiting. From October to early March, UK sunlight is too weak for skin to make it, and NHS advice is that everyone should consider a daily 10 microgram supplement through autumn and winter.

• Ten nutrients carry an authorised GB claim for contributing to the normal function of the immune system. Four of them are worth prioritising as autumn arrives: vitamin D, vitamin C, zinc and selenium.

• Protect your sleep, particularly around a vaccination appointment. Research published in Current Biology found that objectively measured short sleep was associated with a substantially reduced antibody response.

• Keep moving. A Sports Medicine meta-analysis found higher habitual physical activity was associated with a 31 per cent lower risk of community-acquired infectious disease.

• Book your vaccination if you are eligible. NHS flu vaccination opens on 1 September 2026 for some groups and 1 October 2026 for most adult cohorts.

• Eat a wide range of plants rather than a single superfood. Variety is what supports a diverse gut microbiota, and a large proportion of immune tissue sits in the gut lining.

• Some groups are advised to take vitamin D all year round rather than seasonally. There is a list further down.

• Check the dose as well as the nutrient. With vitamin D and zinc in particular, more is not better.

There is a particular morning in September when it stops being summer. The windscreen has misted over. The kitchen is dark at seven. Somebody at work has a cough they cannot shake, and within a fortnight half the office has it too.

Autumn is the one season when what your immune system needs genuinely changes, and unusually for health advice, almost everything on the list is within your control. This is a practical guide to what to take, when to start it, and the habits that do the heavy lifting.

One thing worth saying at the outset. You cannot turn your immune system up like a thermostat, and any product suggesting otherwise is overpromising. What you can do is make sure it has everything it needs to work normally, and clear away the things that get in its way. That list is shorter than the internet suggests, and every item on it is actionable this week.

If you do one thing this month, make it this. Vitamin D is the only nutrient whose availability genuinely changes with the British seasons, and the change is absolute rather than gradual.

From late March or early April to the end of September, most people can make all the vitamin D they need from sunlight on skin. Between October and early March, however, UK sunlight does not contain enough UVB for the skin to make sufficient vitamin D, regardless of how long you spend outdoors

Because vitamin D occurs in only a small number of foods, the NHS advises that everyone should consider taking a daily supplement containing 10 micrograms during autumn and winter.

Vitamin D contributes to the normal function of the immune system. Immune cells carry vitamin D receptors, which is why the nutrient appears so consistently in immunology research, and it is involved in the normal functioning of monocytes and macrophages, the cells that identify and engulf pathogens. It also contributes to the maintenance of normal bones, teeth and muscle function, which is a useful bonus in a season when most people move less.

Getting the dose right

Ten micrograms is the NHS population baseline. Higher strength products are widely used and well tolerated, and the EFSA tolerable upper intake level for adults is 100 micrograms a day from supplements. Our Vitamin D3 2,500 IU with Vitamin K2 (MK-7) pairs the two nutrients deliberately, because K2 is involved in directing calcium into bone rather than soft tissue. If you would rather take vitamin D on its own, or in liquid form, the alternatives sit in our vitamin D range.

Take it with a meal containing some fat. Vitamin D is fat soluble, and absorption is better alongside food than on an empty stomach.

Who should take it all year round

The NHS advises year round supplementation, rather than seasonal, for people who are not often outdoors, including those who are frail or housebound; people living in care homes; people who usually cover most of their skin when outside; and people with darker skin, including those of African, African-Caribbean or South Asian background, because higher melanin reduces the amount of vitamin D the skin can synthesise.

Vitamin C

Vitamin C is water soluble, which means the body holds no meaningful reserve and intake needs to be regular rather than occasional. It contributes to the normal function of the immune system, and separately to the protection of cells from oxidative stress. Our Vitamin C capsules and buffered Vitamin C differ in how gentle they are on the stomach, which for a lot of people is the deciding factor between taking it consistently and quietly abandoning it in week three.

Zinc

Zinc contributes to the normal function of the immune system and to the protection of cells from oxidative stress. It is a nutrient where the dose genuinely matters: sustained high supplemental intakes interfere with copper absorption, and the EFSA tolerable upper intake level for adults is 25 mg a day. Our zinc range is formulated with that ceiling in mind rather than competing on headline numbers.

Selenium

Selenium is the one most people overlook, and the one with the clearest UK angle. British soils are relatively low in selenium, and average national intakes have declined over decades as the wheat supply moved away from selenium rich North American sources. It contributes to the normal function of the immune system and to the protection of cells from oxidative stress. Our selenium range includes several forms, and a practitioner can help you pick between them.

Ten nutrients carry the authorised GB claim that they contribute to the normal function of the immune system. Food first is the sensible principle, and this table is a quick way to check where your diet may already have you covered.

Each capsule of Elderberry Immune Support contains 32 mg vitamin C (40% NRV), 6 mg zinc (60% NRV), 159 mg elderberry extract equivalent to approximately 3 g of elderberries, and 159 mg N-acetyl cysteine. The vitamin C and zinc each contribute to the normal function of the immune system. One capsule a day with food.

Our Respiratory and Immune Support formula combines vitamin D, vitamin C and zinc with N-acetyl cysteine, ginger root, lemon balm, turmeric and piperine, which is a useful option if you would rather cover several bases in a single capsule.

A note on the botanicals in both. We select botanical extracts carefully, considering the plant part, extract strength and standardisation where relevant. Health claims for botanicals remain subject to a specific regulatory position in Great Britain, with many claims still awaiting assessment. Where appropriate, we use botanical claims that are permitted for use under the current on-hold arrangements, rather than extending beyond what those claims support. This allows us to explain why an ingredient has been selected while remaining within the current regulatory framework.

Both sit in our immunity support collection, alongside the single nutrients.

If you took only one section from this article, we would rather it was this one. These are the interventions with the strongest evidence behind them, and none of them require a purchase.

1. Protect your sleep

This is the most underrated item on the list. In March 2023, Karine Spiegel, Eve Van Cauter and colleagues published a meta-analysis in Current Biology examining sleep in the days around vaccination. Where sleep was measured objectively rather than self-reported, short sleep of under six hours a night was associated with a substantially reduced antibody response, with a pooled effect size of 0.79 (95% CI 0.40 to 1.18).

The practical takeaway is specific: aim for seven to nine hours, and be particularly deliberate about it in the few days either side of a vaccination appointment. Worth noting that self-reported sleep showed no significant effect while measured sleep did, which suggests most of us are worse at estimating our own sleep than we think.

2. Keep moving

A 2021 systematic review and meta-analysis by Sebastien Chastin and colleagues in Sports Medicine found that higher levels of habitual physical activity were associated with a 31 per cent lower risk of community-acquired infectious disease (hazard ratio 0.69, 95% CI 0.61 to 0.78). The authors concluded that regular moderate to vigorous activity also increases the potency of vaccination.

In autumn the difficulty is rarely intensity. It is consistency once it is dark at five. Moving your walk, run or class to the morning, or indoors, is usually what keeps it going through to March.

3. Eat a wide range of plants

A substantial proportion of the body's immune tissue sits in the gut lining, and a varied plant intake is what supports a diverse gut microbiota. Variety matters more here than quantity of any single food, so thirty different plants across a week is a more useful target than a daily superfood. Autumn makes this easier rather than harder: squash, brassicas, apples, pears, pulses, root vegetables and the seeds and nuts that go with them.

4. Check whether you are eligible for seasonal vaccinations

For the 2026–27 season, NHS flu vaccination begins from September for some groups, with most eligible adults offered vaccination from October. COVID-19 vaccination is also offered seasonally to eligible groups. If you are eligible, the NHS will provide guidance on when and how to receive your vaccination. The nutrition, sleep and lifestyle measures discussed here should be viewed as complementary to, rather than replacements for, established public-health advice.

Two more that take seconds: open a window for a few minutes a day once the heating goes on, and wash your hands. Both do more against respiratory viruses than anything you can swallow.

Four things worth checking on a label, whoever you buy from.

•     The form, not just the nutrient. Different forms of the same mineral differ in how well they are absorbed and how they sit with people. This is why we make several versions of most minerals rather than one.

•     For adults, the tolerable upper intake level is 100 micrograms (4,000 IU) per day for vitamin D and 25 mg per day for zinc.

•     What is in there besides the active ingredient. We use no binders, flowing agents, caking agents or fillers, with the single exception of plant cellulose as a capsule filler where one is needed.

•     Whether the brand tells you what it cannot claim as readily as what it can.

If you want the detail on that third point, our Red List sets out the additives and fillers we choose not to use, and why.

•     Start a daily vitamin D supplement this month and set a reminder to keep it going to early March.

•     Check whether you fall into one of the year round groups above.

•     Cover vitamin C, zinc and selenium through food where you can, and supplement where you cannot.

•     Check whether you are eligible for a seasonal flu or COVID-19 vaccination and follow the NHS guidance on when it is available to you.

•     Move one regular walk or workout to the morning before the evenings close in.

•     Aim for thirty different plants across the week.

•     Open a window for a few minutes each day once the heating is on.

If you are pregnant or breastfeeding, taking prescribed medication or managing an existing health condition, speak to your GP or a qualified practitioner before starting anything new. You can find a practitioner near you through our directory, browse the full immunity support range, or call our team on 01380 812799 if you would like help working out which form of a nutrient is right for you.

Should I start vitamin D in September or wait until October?

Start now. Skin synthesis becomes unreliable from around the beginning of October, and there is no advantage in waiting for a date. Building the habit while your routine is still settling is easier than adding one in November.

Is 10 micrograms of vitamin D enough?

Ten micrograms (400 IU) is the population baseline the NHS advises everyone to consider through autumn and winter. Some people may be advised to take more by a clinician, particularly if a blood test has shown low levels. The EFSA upper limit for adults is 100 micrograms (4,000 IU) a day.

Can I get everything I need from food instead?

For most of the immune nutrients, yes, and the table above shows where to look. Vitamin D is the exception between October and March, because the food sources are few and the sunlight route is unavailable.

Do I need to take supplements all winter or just when I feel run down?

Consistency is the point. These nutrients support normal function on an ongoing basis rather than acting as a response to symptoms, so a daily habit through the season is more useful than a burst in January.

What is the single most useful thing I can do?