Cold and Flu Season Checklist: 6 Things That Actually Help

By Lindsay Powers  |  Nutritional Therapist & Health Writer, Naturally Healthy News

Published: October 2026  |  Last reviewed: October 2026

Cold and flu season brings the same advice every year: wrap up warm, take your vitamins, wash your hands. Some of it holds up brilliantly under scrutiny. Some of it is more myth than medicine.

Here’s a practical, six-point checklist built entirely on what the trial evidence actually shows, so you can put your effort where it counts this winter.

Step 1: Get Your Vitamin D Sorted

This is the single most evidence-backed step on this list. NHS guidance recommends everyone in the UK, including pregnant and breastfeeding women, take a daily supplement containing 10mcg of vitamin D from October to March, when UK sunlight simply isn’t strong enough for your body to make its own [1]. Vitamin D also has a genuine, EU/UK-authorised health claim for contributing to the normal function of the immune system [2], one of the more solid regulatory approvals in this space.

It’s an easy step to skip precisely because it’s so unglamorous. Set a reminder, keep the bottle somewhere you’ll actually see it, and it’s one of the highest-value five seconds of your day this winter.

Step 2: Protect Your Sleep

Sleep is one of the strongest predictors of whether you’ll actually catch a cold when you’re exposed to one. A study that tracked 164 adults’ real sleep patterns for a week, then exposed them to a cold virus under controlled conditions, found that people sleeping six hours or less a night were 4.2 times more likely to develop a cold than those sleeping over seven, rising to 4.5 times for those under five hours [3]. That’s a striking effect size for a single, modifiable habit.

If sleep has been slipping, this is a good season to prioritise it again, not just for how you feel day to day, but as a real, measurable defence against picking up whatever’s going around.

Step 3: Wash Your Hands Properly and Often

It sounds almost too simple to be worth saying, but the evidence backs it up. A major Cochrane review pooling 19 trials and over 71,000 people found hand hygiene measures produced an 11% relative reduction in respiratory illness overall, rising to a 14% reduction for acute respiratory infections specifically [4]. In practical terms, that’s roughly 22 fewer infections per 1,000 people, a meaningful effect for something free and low-effort.

The evidence is rated low-to-moderate certainty, so it’s not a guarantee, but of everything on this list, it’s about as close to a free win as cold and flu prevention gets.

Step 4: Keep Moving, But Don’t Overdo It

Regular, moderate exercise does support your resistance to colds and other respiratory infections, with research consistently finding fewer infection days in people who stay physically active compared to sedentary adults [5]. A brisk daily walk counts, and it’s one of the more enjoyable items on this list.

The one nuance worth knowing: very intense exercise without adequate recovery can briefly do the opposite. Immune cell counts dip for a couple of hours after a hard, prolonged effort, sometimes called the “open window” in sports medicine, during which the body may be temporarily more susceptible. It’s mainly relevant to endurance athletes training hard, not something the average brisk walk or gym session needs to worry about.

Step 5: Manage Your Stress

This one has particularly elegant supporting evidence. A landmark study exposed volunteers to a cold virus under controlled conditions and found psychological stress levels predicted, in a clear dose-response pattern, who actually went on to develop a cold, driven by a real increase in infection rates, not just how symptoms were reported [6]. Chronic stress appears to blunt the immune system’s ability to fight off a virus once it’s in your system.

Whatever brings your stress down, such as a walk, proper sleep, time with people you like, or breathing practices, counts as a real defensive measure here, not just a nice-to-have. For a fuller rundown of natural options, Fight the Fright with Natural Stress Relievers covers ashwagandha, magnesium, B vitamins, and a few other evidence-backed approaches in more depth.

Step 6: Know What Vitamin C and Zinc Can (and Can’t) Do

Vitamin C’s reputation slightly outpaces the evidence, but it still has a genuine, useful effect. A major Cochrane review found that regular vitamin C supplementation doesn’t reduce your chances of catching a cold in the general population. Still, it does modestly shorten one once you have it: an 8% shorter cold in adults and 14% in children [7]. There’s one striking exception: in people under serious physical stress, marathon runners, skiers, soldiers on sub-arctic exercises, regular vitamin C roughly halved the risk of catching a cold in the first place, a notably different finding worth knowing if that’s you.

Zinc tells a similar story. Taken after a cold starts, oral zinc, in lozenge, tablet or syrup form, may shorten how long symptoms last by around two days, though the evidence is rated low certainty and comes mostly from lozenge trials [8], and zinc also has its own EU/UK-authorised claim for supporting normal immune function [9]. Zinc doesn’t meaningfully prevent colds from happening in the first place, and taste changes or an upset stomach are common enough side effects worth knowing about upfront.

Who Should Be Careful?

• If you take zinc for a cold, stick to the pack’s guidance on duration, prolonged high-dose zinc use can interfere with copper absorption over time.
• If you use a zinc nasal spray or gel, be aware some have historically been linked to loss of smell. A stomach-friendly oral lozenge is the better-evidenced, lower-risk option.
• If you have a kidney condition or take medication affected by vitamin D, check with your GP before starting a vitamin D supplement, even at standard NHS-recommended doses.
• If a cough, fever or other symptoms are severe, don’t improve after a week or two, or you’re in a higher-risk group, see your GP rather than relying on self-care alone.

Frequently Asked Questions

Does vitamin C actually prevent colds?

Not for most people, regular supplementation doesn’t reduce how often you catch a cold in the general population [7]. It does modestly shorten how long a cold lasts once you have one, and it does help prevent colds in people under serious physical exertion, such as endurance athletes.

Is it worth taking zinc when I feel a cold coming on?

It’s a reasonable thing to try. Oral zinc, lozenges, tablets or syrup, taken after symptoms start may shorten a cold by around two days [8], though the evidence quality is only low certainty and comes mostly from lozenge trials, so treat it as worth a go rather than a guaranteed fix.

How much vitamin D should I actually be taking?

NHS guidance is 10mcg daily for everyone in the UK from October to March [1], regardless of age or how much time you spend outdoors, since UK winter sunlight isn’t strong enough for your skin to make it regardless.

Can being stressed really make me more likely to catch a cold?

Yes, and the evidence for it is strong. Higher psychological stress has been shown to directly increase the rate of infection after exposure to a cold virus, not just how unwell you feel about it [6].

Final Thoughts

The good news is that most of these steps are easy to incorporate into your daily routine. Vitamin D, sleep and hand hygiene do most of the heavy lifting this time of year, backed by some of the best evidence on this list. Vitamin C and zinc are worth having on hand too, with realistic expectations about what they can and can’t do.

Put together, it’s a solid, low-effort routine for getting through cold and flu season with fewer sick days. It doesn’t guarantee you’ll never catch anything, but it can help to shift the odds.

References

[1] NHS: Vitamin D. https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/

[2] EFSA Journal, 2015: Vitamin D and Contribution to the Normal Function of the Immune System. https://www.efsa.europa.eu/en/efsajournal/pub/4182

[3] SLEEP, 2015: Behaviorally Assessed Sleep and Susceptibility to the Common Cold. https://pmc.ncbi.nlm.nih.gov/articles/PMC4531403/

[4] Cochrane, 2023: Physical Interventions to Interrupt or Reduce the Spread of Respiratory Viruses. https://www.cochrane.org/evidence/CD006207_do-physical-measures-such-hand-washing-or-wearing-masks-stop-or-slow-down-spread-respiratory-viruses

[5] British Journal of Sports Medicine, 2011: Upper Respiratory Tract Infection Is Reduced in Physically Fit and Active Adults. https://pubmed.ncbi.nlm.nih.gov/21041243/

[6] New England Journal of Medicine, 1991: Psychological Stress and Susceptibility to the Common Cold. https://www.nejm.org/doi/full/10.1056/NEJM199108293250903

[7] Cochrane, 2013: Vitamin C for Preventing and Treating the Common Cold. https://www.cochrane.org/evidence/CD000980_vitamin-c-preventing-and-treating-common-cold

[8] Cochrane, 2024: Zinc for the Prevention and Treatment of the Common Cold. https://www.cochrane.org/evidence/CD014914_zinc-prevention-and-treatment-common-cold

[9] EFSA Journal, 2014: Scientific Opinion on the Substantiation of a Health Claim Related to Zinc and Normal Function of the Immune System. https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2014.3653

Disclaimer: The information in this article is intended for general informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your GP or a qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read here.