Zinc: Effects, Daily Requirement & Recognising Deficiency

In brief: Zinc is an essential trace element involved in more than 300 enzymes. The body needs it every day, but cannot produce or store it in any meaningful amount itself. Depending on sex and diet, the daily requirement is around 7–16 mg. Among other things, zinc contributes to the normal function of the immune system and protects the cells from oxidative stress.

Few minerals are involved in as many processes as zinc – from cell division through the hormone balance to wound healing. And yet an adequate supply is not a given: anyone who eats a plant-based diet or sweats a lot can slip into short supply more easily than they think. This guide shows you what zinc does in the body, how high your requirement is, how to recognise a low supply and which form of zinc is best suited.

The key points at a glance

• Zinc is involved in more than 300 enzymes – hardly any trace element is so versatile.
• Zinc contributes to the normal function of the immune system and protects the cells from oxidative stress.
• It contributes to the maintenance of normal skin, hair and nails – one reason for its popularity in the beauty sector.
• Zinc contributes to normal testosterone levels in the blood and to normal fertility.
• Daily requirement: around 11–16 mg for men, 7–10 mg for women (depending on phytate intake).
• Increased risk of a low supply: vegans, vegetarians, athletes, pregnant women and older people.

What zinc does in the body – the mechanism

Zinc is what is known as a cofactor mineral: more than 300 enzymes need a zinc ion in order to function at all. Zinc is therefore involved in the build-up and running of numerous metabolic pathways. This becomes especially tangible in three examples: it is a component of enzymes that take part in DNA synthesis and cell division – important wherever tissue renews itself quickly, such as in the skin and mucous membranes. It plays a role in the antioxidant protection system and contributes to protecting the cells from oxidative stress. And it is involved in the regulation of immune cells, which is why it has traditionally been so closely linked with the immune system.

The following functions have officially authorised health claims in the EU – we deliberately highlight them here because they show how broadly zinc acts in the body:

Why so many people pay attention to zinc

Zinc appears in very different contexts – and there are good reasons for that. In the beauty sector it is sought after for its role in skin, hair and nails. During the cold season many reach for zinc because of the immune claim, often as a lozenge. Athletes keep it in mind because trace elements are lost through sweat. And anyone who eats a vegan or vegetarian diet keeps a closer eye on zinc, because plant sources are less well utilised due to phytate. Zinc is therefore less of a fad than a classic that plays a role in many life situations.

Historically, the importance of zinc for humans was not really understood until the second half of the 20th century, when links were described between a very low supply and abnormalities in growth and wound healing. Since then, zinc has been regarded as one of the central essential trace elements – today firmly anchored in the official intake recommendations. The fact that it appears in so many everyday situations is therefore not marketing, but an expression of its broad physiological role.

What research is investigating

Alongside the textbook-solid functions, zinc remains the subject of active research. Among other things, researchers are looking at how zinc acts as a “messenger” between cells in the immune system and what role it plays in the maturation of certain immune cells. Another field is bioavailability: how strongly do phytates from different foods really inhibit absorption, and how can it be improved through preparation (soaking, sprouting, fermenting)? The interplay with other trace elements such as copper and iron is also being researched further, because they meet on the same absorption pathways. We deliberately stay with the research direction: much of it is well studied, other aspects still open – and no blanket promise of efficacy for a product can be derived from it.

How much zinc per day?

The DGE states the requirement depending on phytate intake – a detail that is often overlooked. Phytate from grains and legumes inhibits zinc absorption, which is why the recommended value is higher on a plant-based diet. As a guide, for adults it is around 11–16 mg per day for men and 7–10 mg for women. Anyone on a plant-based diet tends to be at the upper end. How high you can go at all and at what point it becomes too much is explained in How long should you take zinc?.

Zinc deficiency: who is at risk and how do you recognise it?

A pronounced zinc deficiency is rare in Germany, but a low supply is certainly possible. Those at increased risk include:

• Vegetarians and vegans – plant-based food contains phytates that bind zinc. More on this in Nutrients for vegans.
• Athletes – trace elements are lost through sweat. Related: Nutrients for strength training & muscle building.
• Older people and people with a one-sided diet.
• Pregnant and breastfeeding women with an increased requirement – see Nutrients for conception & pregnancy.

Signs of a low supply can show up in the skin, hair and nails, among other things – precisely those areas for which zinc has an authorised function. A special case is the laboratory value: because the serum zinc value has only limited significance and fluctuates strongly with time of day and meals, a suspected deficiency should be assessed by a doctor. Which further signs are typical is explored in more depth by this article, complemented by the guide Skin, hair & nails.

Which form of zinc is the best?

As with other minerals, the bound form is decisive for absorption. Organically bound forms are considered particularly well available:

Which form suits which purpose is compared by Zinc bisglycinate vs. gluconate in detail. Whether a lozenge or a capsule makes more sense is explained in Zinc: lozenge or capsule?.

Zinc-rich foods at a glance

Before you reach for a supplement, it is worth looking at your plate – because diet is the most natural source of zinc. Zinc from animal foods is particularly well supplied and utilised; plant sources are valuable too, but their availability is slowed by phytate:

• Meat, offal and cheese – animal zinc is particularly well utilised.
• Pumpkin seeds, sunflower seeds and nuts – the plant-based front-runners.
• Oats and wholegrain products.
• Legumes such as lentils and chickpeas – soaking or sprouting makes the zinc more available.
• Eggs and seafood.

The better your diet supplies zinc, the more likely it is that occasional rather than continuous supplementation will suffice. Why preparation helps determine actual absorption is explained by Bioavailability explained simply.

Intake & tolerability

Zinc is best absorbed on an empty stomach, but can then irritate sensitive stomachs – so many take it with a light meal. Whether with or without food makes more sense is shown by Taking zinc with or without food. It is important to leave a time gap from high doses of calcium, iron or copper, as these minerals interfere with each other during absorption. More on this in Combining supplements correctly. How long taking it makes sense – as a course or continuously – is explained in How long should you take zinc?.

The EFSA states a tolerable total intake of 25 mg per day. Very high amounts of zinc over the long term can disturb the copper balance – so more is not better here. The right interplay is examined by Zinc and copper: the right ratio.

An honest assessment

Established and textbook-solid is the role of zinc as an essential trace element with the officially authorised functions mentioned above – here we are not talking about assumptions, but about recognised knowledge. It is equally clear that an inadequate supply is genuinely possible, particularly on a plant-based diet. Less clear-cut is measurability: the blood value alone reflects the supply only to a limited extent. And more is not better – anyone who permanently exceeds the upper limit risks an imbalance with copper rather than doing themselves any good. If a specific deficiency is suspected, seeing a doctor is the right course.

Suitable products from Scheunengut

In the Zinc category you will find suitable products in various forms – from the capsule to the lozenge. The Trace elements category bundles further trace elements. Zinc is also a central building block for Skin, hair & nails and a strong immune system – for the latter it is also worth a look at the Immune system category.

Frequently asked questions (FAQ)

How much zinc do you need per day?

The daily requirement for adults is around 11–16 mg for men and 7–10 mg for women. The DGE grades the value according to phytate intake: anyone on a plant-based diet tends to be at the upper end, because phytate from grains and legumes inhibits zinc absorption. The tolerable total intake from all sources is 25 mg per day.

How do you recognise a zinc deficiency?

Signs of a low supply can show up in the skin, hair and nails, among other things – that is, the areas for which zinc has an authorised function. Because the serum zinc value in the blood has only limited significance and fluctuates strongly, a suspected deficiency should be assessed by a doctor rather than relying on a laboratory value alone.

Which form of zinc is the best?

Organically bound forms such as zinc bisglycinate (chelate) and zinc citrate are considered particularly well available and well tolerated. Zinc gluconate is proven and often contained in lozenges. Zinc oxide is inexpensive, but tends to be absorbed less well. The “best” form depends on the purpose – for the cold season, for example, lozenges are popular.

Who should pay particular attention to their zinc supply?

An increased risk of a low supply applies to vegans and vegetarians (phytate binds zinc), athletes (loss through sweat), older people and people with a one-sided diet, as well as pregnant and breastfeeding women with an increased requirement. For these groups it is worth deliberately planning in zinc-rich foods or keeping an eye on the supply.

How we at Scheunengut ensure verified purity from raw material to tin, you can find out on our page about the Clean Earth Badge.