At a glance
Zinc is an essential trace element involved in immune function, cell protection and more than a hundred enzymes.
In Vykea: zinc bisglycinate (5 mg zinc per sachet)
The body cannot store significant amounts of zinc, so regular intake is important.

Zinc is an essential trace element and, after iron, the second most abundant trace element in the human body. An adult carries a total of about two to three grams of zinc, mainly in the muscles, bones, skin, liver and male reproductive organs. The body cannot store zinc to any significant extent, which is why regular intake from food is important. Zinc is a component or activator of well over a hundred enzymes and is involved in immune function, cell division, wound healing, hormone metabolism and the protection of cells from oxidative stress. In Omnia All-In-One we use zinc bisglycinate at 5 mg zinc per sachet. This entry explains the forms, food sources, functions, requirements, laboratory testing, possible signs of deficiency and interactions of zinc.

In food supplements, zinc occurs in various compounds, as pure zinc metal cannot be utilised. A distinction is mainly made between inorganic salts and organically bound forms.

Inorganic forms include zinc oxide and zinc sulphate. Zinc oxide has a high zinc content but tends to be less well absorbed than organically bound forms. Organic compounds include zinc gluconate, zinc citrate, zinc acetate and zinc lactate, as well as forms bound to amino acids such as zinc bisglycinate and zinc histidine. Organically bound forms are generally regarded as readily available.

Zinc bisglycinate is a chelated form. In it, a zinc ion is stably enclosed by two molecules of the amino acid glycine. This chelate structure protects the zinc in the digestive tract from forming poorly soluble complexes with other food components such as phytates and can thus promote absorption. Glycine is also a small, readily absorbed molecule. In the specialist literature, zinc bisglycinate is counted among the readily bioavailable forms of zinc, which are also described as gentle on the stomach. Omnia uses zinc bisglycinate.

Zinc occurs in both animal and plant foods. Particularly high levels are found in oysters and other shellfish, as well as in red meat and offal such as liver. Cheese and other dairy products, eggs and fish are also good sources. On the plant side, wholegrain products, rolled oats, wheat germ, pulses, nuts and oilseeds contribute.

What matters is not only the zinc content but also its availability. Zinc from animal foods is generally better absorbed than zinc from plant sources. The reason is the content of phytic acid (phytate) in cereals, pulses and seeds. Phytate binds zinc in the gut and reduces its absorption. A high calcium intake can intensify this effect. Soaking, sprouting, sourdough fermentation and fermenting can lower the phytate content and improve zinc availability. Animal protein in a meal improves the utilisation of zinc from plant sources.

Zinc is a component or cofactor of well over a hundred enzymes and is therefore involved in a wide range of metabolic processes:

The next section shows which of these functions are authorised as health claims.

The following health claims are authorised for zinc in the EU:

These claims apply to zinc in general and therefore also to the form used in Omnia, zinc bisglycinate.

The German Nutrition Society (DGE) revised the reference values for zinc in 2019. For adults and adolescents aged 15 and over, the requirement now depends on phytate intake, as phytate reduces zinc absorption. With a predominantly plant-based diet with a high proportion of wholegrain products, the requirement is higher than with a mixed diet.

The nutrient reference value for labelling (NRV) is 10 mg per day. The European Food Safety Authority (EFSA) gives a tolerable upper intake level of 25 mg per day from all sources for adults.

In some life stages and situations, zinc requirements are higher or zinc status is poorer: during growth phases in children and adolescents, during pregnancy and breastfeeding, in older people and in people who follow a predominantly plant-based diet. Vegetarians and vegans more often have a zinc intake below the reference value, as plant sources are rich in phytate and the zinc they contain is less available.

Increased requirements or increased losses also occur when absorption from the gut is impaired (for example with chronic inflammatory bowel disease or persistent diarrhoea), with liver disease, with diabetes mellitus, in people who sweat heavily and endurance athletes, with regular alcohol consumption and when taking certain medicines (see the Interactions section). Requirements are also increased after operations, with burns and during phases of increased tissue regeneration.

The role of zinc in immune defence has been well studied. Zinc is needed for the development and function of numerous immune cells, including T cells and natural killer cells, and is involved in controlling inflammatory responses. Zinc deficiency can be associated with increased susceptibility to infections and weakened mucosal barriers. The scientific literature describes the relationship between zinc status and immune function in detail, for example in the review by Wessels and colleagues.

This explains why the EU claim on the contribution of zinc to the normal function of the immune system is authorised. It does not imply any statements that go beyond this authorised wording, such as on the treatment or prevention of infections.

Note: Whether additional zinc intake is advisable in an individual case should be left to a doctor to decide.

Zinc status is determined by a doctor from a blood sample. It is usually measured in serum or plasma (reference range approximately 0.8 to 1.4 mg/l). However, this measurement is of only limited informative value, as around 90% of zinc is located inside the cells and the serum value is influenced by inflammation, food intake and time of day, among other things. Measurement in whole blood (reference range approximately 4 to 8 mg/l), which also captures the intracellular fraction, can be more informative.

Correct sample collection is important: even slight haemolysis (breakdown of red blood cells) distorts the zinc value, as zinc escapes from the cells. Blood should therefore ideally be taken in the morning after fasting.

Note: Interpreting the values and any supplementation should be left to a doctor.

Zinc deficiency can manifest itself in many ways, as zinc is involved in so many processes. Possible signs include increased susceptibility to infections, delayed wound healing, skin changes (such as dry or inflamed skin), hair loss, brittle nails and white spots on the nails. Loss of appetite, disturbances of the sense of taste and smell, tiredness and changes in concentration and mood are also possible. In children, a longer-lasting deficiency can impair growth and development.

Such signs are not conclusive and can have many causes. Zinc deficiency can also be difficult to detect with routine laboratory tests.

Note: Investigation and diagnosis should be left to a doctor.

The following information summarises the areas of use described in the specialist literature.

Note: This information does not replace medical advice; targeted or higher-dose use should be left to a doctor.

A long-term high zinc intake should only exceed the tolerable upper intake level of 25 mg per day under medical supervision. Very high single doses can cause nausea, a metallic taste, headaches or gastrointestinal complaints. Particular caution is needed with impaired kidney function. Zinc is preferably taken between meals or in the evening, as phytates and some minerals from food reduce its absorption.

Zinc interacts with other minerals, as they partly share the same absorption pathways. A high intake of iron, calcium or copper can reduce zinc absorption, and vice versa. Phytates from plant foods bind zinc in the gut and reduce its availability. The amino acid histidine, on the other hand, can promote zinc absorption.

Various medicines affect zinc status. Antacids and certain antibiotics from the tetracycline and fluoroquinolone groups form poorly soluble complexes with zinc; a time interval of several hours is recommended here, which also ensures that the antibiotics remain effective. Certain diuretics, ACE inhibitors, corticosteroids and oestrogens (for example in oral contraceptives) can increase zinc excretion or reduce its absorption.

Note: If you take such medicines, you should check with a doctor before taking additional zinc.

Zinc and copper are in balance with each other. A permanently very high zinc intake can impair the absorption of copper in the gut and contribute to copper deficiency in the longer term, which is why the ratio of the two trace elements should be taken into account. The background is that a high zinc intake causes the intestinal cells to produce more of the binding protein metallothionein, which binds copper more strongly and is excreted with the shed cells. This effect is mainly relevant with high, long-term intake, not with an intake that meets requirements within the reference values. Reviews of the copper-zinc ratio describe this reciprocal relationship and recommend keeping an eye on both trace elements with prolonged higher zinc intake. Anyone who wants to take higher amounts of zinc over a long period should therefore have the ratio to copper monitored by a doctor.

Zinc is also involved in vitamin A metabolism. The specialist literature describes two points of action: firstly, zinc is needed for the formation of retinol-binding protein (RBP), the transport protein that delivers vitamin A from the liver to the tissues. Inadequate zinc status can reduce this formation and thus impair the availability of vitamin A in the blood. Secondly, zinc is involved in zinc-dependent enzymes that convert retinol to retinal, a step that plays a role in the visual cycle of the retina, among other things. These general relationships from nutritional science explain why zinc and vitamin A are considered together in the literature. They are descriptive metabolic relationships, not a promise of effect for any individual product.

You can find more about the partner nutrient in the Vitamin A entry.

Zinc bisglycinate is one of the chelated zinc compounds. The zinc ion is stably enclosed by two glycine molecules, like a clamp. This structure can protect the zinc in the digestive tract from forming poorly soluble complexes, for example with phytates from plant foods, and is described in the specialist literature as having good bioavailability and good gastric tolerability. Glycine itself is a non-essential amino acid produced by the body. In Omnia, zinc is present as zinc bisglycinate.

Zinc is contained in Omnia All-In-One:

The amount stated refers to the elemental zinc contained, not to the weight of the whole compound. The % of NRV is based on the labelling value of 10 mg. One daily dose corresponds to one sachet.

Food supplements are not a substitute for a balanced, varied diet and a healthy lifestyle.

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