Nutrients for the immune system: the big overview

The short answer: Vitamin C, vitamin D, zinc and selenium contribute to the normal function of the immune system – complemented by vitamin A, vitamin B6, vitamin B12, folate, iron and copper. A colourful, plant-forward diet supplies most of them. It becomes a real issue above all with vitamin D during the dark season, as well as with zinc and iron on a purely plant-based diet.

As soon as the days grow shorter and the first colleague starts coughing their way through the office, many people think: “I should do something for my immune system.” Usually vitamin C then lands in the shopping basket. Yet the immune system is far more than a single vitamin – it is a widely branched network that relies on a whole series of micronutrients. This guide provides exactly that overview.

A network – not a single switch

“Immune system” spans many levels: the skin and mucous membranes as the first barrier, phagocytes that render intruders harmless, and antibodies as targeted defence. Different nutrients are involved in these various processes. That is why it falls short to reduce the immune system to a single substance – what counts is the overall supply. The following table shows which nutrients carry an authorised claim for normal immune function and where they are found.

Vitamin C and zinc: the familiar classics

Vitamin C is the nutrient most people think of first. It not only contributes to normal immune function, but also to the protection of cells from oxidative stress and to a normal energy-yielding metabolism. The body can neither produce nor store vitamin C itself – a regular intake spread across the day therefore makes sense. More in Vitamin C: effects and daily requirement.

Zinc is involved in countless enzymatic reactions and contributes to normal immune function, to the protection of cells from oxidative stress and to normal DNA synthesis. Forms and sensible use are explained in Zinc: effects and daily requirement.

Vitamin D and selenium: often underestimated

Vitamin D plays a special role: the body produces it itself via the skin given sufficient sunlight – yet during the winter months the sun sits too low at our latitudes, so its own production drops sharply. Vitamin D contributes to normal immune function and to the maintenance of normal bones. Background in The dark season: light and vitamin D and, on the question of dosage, Vitamin D: dosage, blood level, winter.

Selenium is often present only in small amounts in European soils. It contributes to normal immune function, normal thyroid function and the protection of cells from oxidative stress. Details in Selenium: effects and daily requirement.

Vitamin A, B vitamins, iron and copper: the further contributors

Besides the four classics, further nutrients belong on the list. Vitamin A contributes to normal immune function and to the maintenance of normal mucous membranes – and the mucous membranes of the airways and gut are a crucial outer barrier. Vitamin B6, B12 and folate are likewise involved in normal immune function, as are the trace elements iron and copper. This underlines the common thread: it is worth keeping the supply broadly in view rather than betting on a single substance. How to prepare in autumn is shown in Building up the immune system in autumn; for winter, Strengthening the immune system in winter is a good fit.

What research is investigating

That the nutrients mentioned contribute to normal immune function is the basis of the authorised health claims – well-established knowledge about their role in immune cells and barriers. What is being actively and at times controversially researched is whether an additional intake beyond a covered requirement brings any further benefit. The broad consensus points in one direction: those who benefit most are people in whom a nutrient is actually in short supply – such as vitamin D in winter, or zinc and iron on a purely plant-based diet. Where the supply is already good, no additional effect is to be expected from “more”. That is not a weakness but an honest assessment that spares you expensive mistaken purchases.

How to cover your requirement in everyday life

The good news: a colourful, plant-forward diet supplies most of the immune-relevant nutrients. A few rules of thumb:

• Colour on the plate every day: colourful vegetables and fruit provide vitamin C and provitamin A.
• Wholegrains and seeds contribute zinc; Brazil nuts are a well-known source of selenium (a few are enough).
• Legumes regularly for iron, copper and folate.
• Keep an eye on vitamin D in winter – it can then hardly be covered via the sun.

How to combine several supplements sensibly is explained in Combining supplements correctly; the trio of vitamin C, D and zinc is explored in more depth in Immune system: vitamin C, D and zinc.

In practice: combine sensibly instead of stacking at random

If you supplement individual nutrients, it is worth looking at the interplay. A few proven points:

• Spread vitamin C across the day: the body does not store it, so several small portions are more sensible than one large one.
• Vitamin D is fat-soluble: it is better absorbed with a meal containing fat – so don’t take the drops on an empty stomach.
• Don’t keep zinc very high long-term: and consider it in relation to copper, as the two are connected.
• Selenium in moderation: a few Brazil nuts cover the requirement, and a lasting excess is not desirable.

Anyone using several supplements will find practical guidance in Which supplements not to take together? on which combinations are better separated in time.

Honestly assessed: what nutrients cannot do

As important as a good supply is – micronutrients are no shield against infections and are no substitute for a healthy lifestyle. They contribute to the normal function of the immune system when the intake is covered; those who are already well supplied gain nothing further from additional amounts. At least as important are enough sleep, exercise in the fresh air, stress relief and hand hygiene. In the case of frequent or persistent infections, the cause should be clarified by a doctor.

Matching products from Scheunengut

In the Immune system category you will find products specifically put together around the body’s defences. Individual nutrients such as Vitamin C, Vitamin D, Zinc and Selenium can also be discovered in the overview Vitamins, minerals & trace elements. All products are lab-tested and made in Germany.

Frequently asked questions (FAQ)

Which nutrients are most important for the immune system?

The classics with an authorised claim for normal immune function are vitamin C, vitamin D, zinc and selenium. Added to these are vitamin A, vitamin B6, B12, folate as well as iron and copper. Since the immune system is a broad network, it is worth looking at the overall supply rather than at a single substance.

Should I supplement vitamin D in winter?

The body forms vitamin D via the skin only with sufficient sun – during the winter months the sun sits too low at our latitudes, so its own production drops sharply. That is why vitamin D is a topic precisely then. For the right amount, your individual blood level is helpful; if in doubt, this can be clarified with a doctor.

Does vitamin C help with colds?

Vitamin C contributes to the normal function of the immune system and to the protection of cells from oxidative stress – that is the authorised framework. A promise to prevent or treat colds is not associated with it. Since the body does not store vitamin C, a regular intake spread across the day makes sense.

Is diet enough, or do I need supplements?

A colourful, plant-forward diet covers most of the immune-relevant nutrients well. Individual nutrients such as vitamin D in winter, or zinc and iron on a purely plant-based diet, can run short – here a targeted supplement can make sense. A blanket high-dosing where the supply is already good, on the other hand, brings no additional benefit.