How to strengthen your immune system: habits that count

There is no single trick to strengthen your immune system. None of them promises you will never get ill.

The rest — supplements, shots, miracle capsules — takes up much less space than advertising suggests. And in some cases, it can be money badly spent or even counterproductive.

The habits that really make a difference (and the ones that don't)

There are factors that the evidence links to a higher risk of micronutrient deficiency, such as older age, pregnancy or problematic alcohol consumption. There is also a fifth, which is not really a habit but a condition: making sure you have no nutritional deficiencies due to dietary restriction, illness or age. That is where the conversation about vitamins and minerals stops being abstract.

What is not on the list? "Detox" and "immune boost" in a bottle are attractive expressions, but the idea that taking something every day prevents infections is not supported by the available evidence. The phrase "strengthen immunity" is attractive but misleading: the immune system is not a muscle you train with repetitions.

Why sleep counts more than any supplement

What works in practice: a more or less fixed bedtime and waking time, even at the weekend; low light in the hour before bed; and avoiding caffeine after mid-afternoon if you are sensitive. If you wake up tired every day, the problem may not be "lack of vitamins" — it could be fragmented sleep, apnoea or anxiety. It is worth talking to a doctor before buying bottles.

Food: variety before any pill

The claim that zinc supplements strengthen the immune system to prevent infections is not supported by the available sources. Variety matters because different micronutrients take part in different processes — and because a monotonous diet can contribute to nutritional gaps.

Zinc contributes to the normal function of the immune system (an authorised claim in the European Union), but the claim that zinc supplements strengthen the immune system to prevent infections is not supported by the available sources. Zinc contributes to the normal function of the immune system, but that does not mean that taking extra doses above what you need produces an extra effect. Supplementation only makes sense when there is a real gap — and that is where the conversation changes.

Who may be at risk of gaps? Older adults, pregnant women and people with alcohol use disorders are among the groups at higher risk of micronutrient deficiency. People who restrict calories, have a small appetite, are ill or eliminate entire food groups may also have deficiencies, including zinc. Children with inflammatory bowel disease, coeliac disease or who take proton pump inhibitors long term are particularly susceptible to zinc deficiency. If you recognise yourself in any of these cases, the conversation about supplementation should be had with a healthcare professional — not decided alone.

Movement and stress: what the evidence allows us to say

You don't need marathons; brisk walks, swimming or anything you do regularly counts.

Chronic stress is the other side of the coin. What we know is that managing stress — with sleep, movement, quality time and, if necessary, psychological support — is part of a healthy lifestyle.

How to fit this into a real day

Habits don't live in a laboratory. They live in days with meetings, children, traffic and tiredness. The key is to anchor each habit to something you already do:

• Sleep: set a cut-off time for screens and stick to it as you would stick to a meeting.
• Food: fill half your plate with vegetables at lunch and dinner. It's simpler than counting nutrients.
• Movement: tie it to an existing routine — get off one stop before the tube, walk after lunch.
• Stress: set aside five minutes a day for something that genuinely calms you, not for scrolling.

On the days that go badly — and they will — don't try to make up for everything at once. Pick up again the next day. Consistency over weeks matters more than perfection on one day.

Common mistakes that undo the effort

The first is trusting a supplement to make up for bad nights' sleep and poor food. The second is taking high doses of vitamins or minerals "just in case": more is not better, and the data on high doses of zinc are not reassuring — in animal models of ALS high doses were harmful, and the human data are limited to a single trial. The third is ignoring persistent signs — extreme tiredness, recurring infections, unexplained weight loss — and putting them down to "lack of defences" instead of seeking help.

There are also mistakes that matter less than people think: not eating "superfoods" every day, not taking a shot in the morning, not drinking lemon water on an empty stomach. None of that is obligatory. What counts is the overall pattern.

When does a supplement make sense?

If you already cover sleep, food, movement and stress, and still feel something is missing, a supplement can be considered — but as a complement, never as a substitute. The evidence on zinc, for example, is mixed: some studies suggest effects in specific contexts, but the idea that zinc "strengthens immunity to prevent infections" is not supported by the available data. That is different from promising protection against flu.

If you choose a supplement, choose one with doses that do not exceed what you need and check the label. Immunity & Defense Gummies with Echinacea combine, per two-gummy serving, vitamin C, zinc, vitamin D3, selenium, echinacea extract and Lactobacillus rhamnosus. Multivitamin Gummies cover a wider spectrum of vitamins and minerals. Neither replaces the habits above, and neither promises you will not get ill. They are intended for adults; pregnant or breastfeeding women, or people with an illness or on medication, should talk to a healthcare professional before taking them.

What to do if, after two or three weeks, you notice no difference

First: don't expect miracles in two weeks. Sleep and eating habits take time to consolidate, and the goal is not to feel a "boost", it is to maintain normal functioning over months. If, even so, you feel something is not right — frequent infections, tiredness that won't go away, recurring fever — the next step is not to buy another bottle. It is to talk to a doctor or pharmacist.

The conversation with a professional is especially important if you have a chronic illness, take regular medication, are pregnant or breastfeeding, or suspect a deficiency. Only a clinical assessment can tell you whether you need supplementation and at what dose. The rest is trial and error — and your body deserves more than that.

There is no secret formula. There is sleep, varied food, movement, less stress and, when necessary, professional help. It is less exciting than the packaging promises, but it is what the evidence supports.