Zinc is an essential mineral involved in numerous processes in the body and is found both in foods and in food supplements. It is commonly associated with the immune system, skin, hair and even testosterone, but many of these associations need to be explained properly to avoid exaggerated expectations.
Understanding the benefits of zinc means knowing what functions it actually performs, which foods provide it, why its absorption can vary depending on our diet and when supplementation may be worth considering.
As with other minerals, having an adequate amount is important, but consuming more zinc than necessary does not automatically provide greater benefits and may even be counterproductive.
What is zinc and what does it do?
Zinc is an essential mineral that our body needs in small amounts, but it is involved in a wide variety of physiological processes.
Among other functions, it contributes to nutrient metabolism, normal protein and DNA synthesis, cell division and normal immune system function.
It also contributes to the normal maintenance of skin, hair, nails, bones and vision.
Precisely because it is involved in so many different functions, zinc appears in supplements aimed at very different goals. This does not mean that it is a miracle product, but rather that it is a micronutrient required for normal body function.
Main benefits and functions of zinc
Contributes to normal immune system function
One of the best-known associations is the relationship between zinc and the immune system.
Zinc contributes to the normal function of the immune system.
This helps explain why it is often combined with other micronutrients such as vitamin C or vitamin D in supplements related to immune support.
However, we need to distinguish between contributing to normal immune system function and claiming that taking zinc prevents illness or cures specific infections.
A zinc supplement does not replace preventive measures or medical treatments when these are necessary.
We saw something similar when discussing the benefits of vitamin D: contributing to normal immune function does not automatically turn a nutrient into a medicine.
Contributes to the maintenance of normal skin
Zinc also contributes to the maintenance of normal skin.
For this reason, it often appears in supplements designed for skin care and in formulas that combine different vitamins, minerals and other nutrients.
However, we should not turn this function into the claim that taking zinc eliminates acne, cures skin problems or guarantees perfect skin.
Skin condition depends on many factors, and certain changes require professional assessment.
Contributes to the maintenance of normal hair and nails
Zinc also contributes to the normal maintenance of hair and nails.
This explains its presence in many supplements aimed at personal care.
However, significant hair loss or very weak nails can have many different causes and should not automatically be attributed to zinc deficiency.
Taking supplements without knowing the real cause may not solve the problem and may also lead us to consume unnecessary amounts of the mineral.
Contributes to the protection of cells from oxidative stress
Another recognised function of zinc is its contribution to the protection of cells from oxidative stress.
Oxidative stress is part of different physiological processes and occurs when there is an imbalance between certain reactive species and the mechanisms our body has to manage them.
The fact that zinc contributes to this protection does not mean that it acts as an absolute shield against ageing or disease.
It is a normal physiological function within a much more complex system.
Contributes to normal cognitive function
Zinc contributes to normal cognitive function.
This claim should not be interpreted as meaning that taking zinc automatically increases intelligence, memory or concentration.
Having the nutrients required for the body to maintain normal functions is one thing; expecting an additional dose to improve those functions when nutritional status is already adequate is something different.
Zinc, fertility and testosterone: what can we really say?
This is one of the areas where exaggerated messages are especially common.
Zinc contributes to normal fertility and reproduction and also contributes to the maintenance of normal testosterone levels in the blood.
The important word here is normal.
This does not mean that taking zinc raises testosterone above normal levels or that it acts as a hormonal booster.
Nor does it mean that a zinc supplement is a treatment for fertility problems.
These functions tell us that maintaining an adequate zinc status is important for normal physiological processes related to reproduction and hormonal balance, but they do not justify promises of extraordinary results.
Other important functions of zinc
In addition to the functions already mentioned, zinc is involved in many other normal processes in the body.
- the maintenance of normal bones;
- the maintenance of normal vision;
- normal DNA synthesis;
- normal protein synthesis;
- normal macronutrient metabolism;
- normal carbohydrate metabolism;
- normal fatty acid metabolism;
- normal vitamin A metabolism;
- normal acid-base metabolism;
- the process of cell division.
This wide range of functions helps explain why zinc is relevant as part of a balanced diet.
Which foods contain zinc?
Before thinking about supplements, it is worth remembering that zinc can be obtained from many foods.
- oysters and other shellfish;
- meat;
- fish;
- eggs;
- dairy products;
- legumes;
- nuts;
- seeds;
- whole grains.
However, not all the zinc present in food is absorbed in the same way.
This is where an especially interesting factor appears when talking about diets rich in plant foods: phytates.
Zinc and phytates: why absorption also matters
Some plant foods, especially whole grains, legumes, seeds and nuts, contain phytates.
Phytates can bind to zinc in the intestine and reduce the proportion that our body absorbs.
This does not mean that these foods are harmful. On the contrary, they can certainly form part of a healthy diet.
It simply means that the amount of zinc in a food is not the only factor that determines how much zinc our body will ultimately be able to use.
For this reason, zinc requirements can vary depending on the overall composition of the diet.
Do vegetarians or vegans need more zinc?
A vegetarian or vegan diet can provide zinc, as there are several plant-based sources such as legumes, seeds, nuts and whole grains.
However, these diets also tend to contain more phytates, which can reduce zinc absorption.
This does not mean that every vegetarian or vegan automatically needs a supplement.
It does mean that it is worth paying attention to food selection and preparation and ensuring that the diet is well planned.
Traditional techniques such as soaking, sprouting and fermentation can reduce some of the phytate content in certain foods and improve mineral availability.
How much zinc do we need per day?
In the case of zinc, it is not particularly useful to give one single figure that applies to all adults.
European reference values take into account, among other factors, the amount of phytates in the diet because they affect zinc absorption.
For this reason, reference intakes for adults vary depending on sex and the characteristics of the diet.
As a general guide, European reference values are approximately 7.5 to 12.7 mg per day for adult women and 9.4 to 16.3 mg per day for adult men, depending on phytate intake.
This helps explain why it does not always make sense to compare our diet with a single figure found online.
When may zinc supplementation be useful?
Not everyone needs to take a zinc supplement.
Supplementation may make sense when the diet does not adequately meet requirements, when certain circumstances increase the risk of insufficient intake or when there is a professional recommendation.
Some situations may require particular attention to zinc status, such as certain gastrointestinal problems that reduce absorption, some forms of bariatric surgery or very restrictive diets.
This does not mean that being in one of these groups automatically means having a deficiency.
The situation needs to be assessed individually.
How can we know if we have a zinc deficiency?
Assessing zinc status is not always straightforward.
Blood zinc levels can provide useful information, but there is no single perfect marker that can diagnose every situation on its own.
In addition, possible signs such as changes in hair, skin, appetite or taste can have many different causes.
For this reason, it is not advisable to self-diagnose a zinc deficiency based only on non-specific symptoms.
If there is a genuine suspicion of deficiency, certain medical conditions or circumstances that may affect absorption, professional assessment is the most appropriate approach.
Types of zinc in supplements
When reading labels, we can find different forms of zinc.
Commonly used forms include zinc gluconate, zinc citrate, zinc sulfate, zinc acetate and zinc oxide, among others.
The amount we are really interested in comparing is the amount of elemental zinc provided by the product serving.
For example, the stated amount of a particular zinc salt does not mean that the entire amount corresponds to zinc itself.
This is why it is important to read the complete nutritional information and check how many milligrams of zinc the daily serving actually provides.
How to choose a zinc supplement
Check how much zinc it actually provides
We should not choose a supplement based only on marketing expressions such as “high strength” or on the amount of the compound used.
What matters is the amount of elemental zinc provided by the daily serving.
Check which other nutrients it contains
Zinc is often combined with other vitamins and minerals.
This can be practical in certain formulas, but it also makes it more important to review the other supplements we use.
Combining several products without checking their composition can lead us to unnecessarily duplicate certain nutrients.
As we saw when discussing the benefits of magnesium, a label should be assessed as a whole rather than only by the ingredient highlighted most prominently.
Do not confuse a high dose with a better product
A higher dose does not automatically make a supplement a better option.
This is particularly important with zinc because excessive intake over time can interfere with the metabolism of other minerals, especially copper.
Does more zinc mean more benefits?
No.
In Europe, a tolerable upper intake level of 25 mg of zinc per day has been established for adults.
This amount refers to total intake and should not be interpreted as a recommended daily dose.
The existence of a safety limit does not mean that we should try to get close to it.
A balanced diet combined with unnecessarily high supplementation can result in consuming considerably more zinc than we actually need.
Excessive intake over time can cause adverse effects and, in particular, affect copper status in the body.
Zinc and copper: a relationship worth considering
Zinc and copper share certain mechanisms related to their absorption and metabolism.
When high amounts of zinc are consumed for prolonged periods, copper absorption may decrease.
This is one reason why using high doses of zinc for long periods is not advisable without a clear reason and without supervision when this is necessary.
Once again, the idea that “if a little is good, more must be better” does not work in nutrition.
When is the best time to take zinc?
There is no single mandatory time of day for taking zinc.
The most important thing is to respect the recommended dose and choose a time that makes it easier to maintain a consistent routine.
Some people may experience digestive discomfort when taking certain zinc supplements on an empty stomach, so the specific instructions for the product should always be used as a reference.
Zinc can also interact with some medicines and other minerals when taken at the same time.
If we regularly take medication, especially certain antibiotics, it is advisable to check how the doses should be spaced.
Zinc, exercise and performance: putting expectations into context
Zinc contributes to normal macronutrient metabolism and normal protein synthesis and contributes to the maintenance of normal testosterone levels in the blood.
This helps explain why it appears in many products aimed at active people and athletes.
However, having enough zinc does not mean that consuming additional amounts will automatically increase muscle mass, strength or testosterone.
Sports performance depends mainly on training, nutrition, rest and planning.
Supplements can form part of that strategy when there is a specific need, but they do not replace the fundamentals of good training and a consistent routine.
Zinc: important, without turning it into a miracle product
The benefits of zinc are linked to its role in numerous normal functions of the body.
It contributes to normal immune system function, the normal maintenance of skin, hair, nails, bones and vision, normal cognitive function and the protection of cells from oxidative stress, among other functions.
It also contributes to normal fertility and reproduction and to the maintenance of normal testosterone levels in the blood.
All of this makes zinc an important mineral without the need to attribute exaggerated properties to it.
Food should always be our first starting point.
If we decide to use a supplement, it is worth checking the actual amount of elemental zinc, the daily serving, the other ingredients and any other supplements we already use.
Above all, we should remember that a higher amount does not necessarily provide greater benefits.
As with other micronutrients, supplementation makes the most sense when it is used to complement a balanced diet and healthy habits, rather than replace them.