Zinc is an important mineral that you should get through your diet every day. But as a bodybuilder do you need extra of it? So should you use a zinc supplement? And does such a supplement also do something for your testosterone level? Zinc from A to Z.

WHAT IS ZINC?

Zinc is a mineral. Minerals are salts that arise from dead nature. They are important for, among other things, your body tissues, your nerve functions, bones and teeth. Your body cannot make minerals on its own. So you have to get them through your diet or in the form of supplements. Zinc belongs to a special group of minerals, namely the trace elements. These are minerals that the body needs very little.

Zinc is also an antioxidant. After all, the term antioxidants is a collective name for substances such as vitamins E and C, trace elements such as selenium and zinc, and bioactive substances such as those present in vegetables and fruit. Antioxidants protect cells and tissues against so-called free radicals. Free radicals are formed during normal metabolism, but also when smoking and sunbathing. They are aggressive substances that can cause damage to cells and tissues, also known as oxidative damage.

WHAT IS ZINC GOOD FOR?

Zinc is a multifunctional nutrient: it plays a role in many functions of the body.

Zinc is a very active mineral. It is part of hundreds of different chemical reactions (enzymes) and is found in cells throughout the body. Zinc is necessary for the body’s defense/immune system to work properly. It plays a role in cell division, cell growth, wound healing, skin repair and metabolism (more precisely the breakdown of carbohydrates, fats and proteins).

About 30 percent of the body’s zinc stores are located in bone. Zinc is therefore also important for the formation and maintenance of strong bones.

Zinc is also necessary for the functioning of the senses smell, taste and sight. It also contributes to a good hormone balance and fertility. During pregnancy, infancy and childhood, the body needs zinc to grow and develop properly. Zinc also improves the action of insulin.

Finally, zinc has a positive influence on normal cognitive functions, such as intelligence, memory, attention and concentration.

A zinc deficiency leads to a lack of appetite, less sensitive senses, slow wound healing and pain in the skin and connective tissues.

WHAT DOES ZINC CONTAIN?

Zinc is mainly found in the following foods:

• meat, especially red meat
• seafood, such as oysters, mussels and shrimp
• legumes, such as chickpeas, lentils, and beans
• nuts, such as pine nuts, peanuts, cashews, and almonds
• dark chocolate
• dairy products, such as cheese and milk
• eggs
• whole grains such as wheat, quinoa, rice, and oats
• seeds and kernels, such as hemp seeds, pumpkin seeds and sesame seeds
• potatoes

Oysters contain by far the highest amount of zinc of all foods: a whopping 182 mg per 100 g. Ground beef (10mg/100g), dark chocolate (9.6mg/100g) and peanuts (3.3mg/100g) also provide quite a bit of zinc.

Fruits and vegetables contain relatively little zinc, which makes it sometimes difficult for vegetarians and vegans to get the recommended daily amount of zinc (see below).

HOW MUCH ZINC DO YOU NEED?

Zinc is usually not a major component of any organ or function in the body, but without enough zinc, many processes in the body cannot function properly. In addition, the body is unable to store zinc. It is therefore necessary to get enough every day.

The Nutrition Center recommends a minimum of 9 mg per day for adult men and 7 mg per day for adult women ^[ i ] .

So that’s actually quite little. In the Netherlands, according to the Nutrition Center, there are no known cases of zinc deficiency.

According to the Nutrition Center, it is also virtually impossible to get too much zinc through food. If someone already takes in too much zinc, it is usually the result of supplementation. Taking a high dose of zinc tablets every day for a long time can reduce the absorption of copper and iron, which are also essential foods.

40 milligrams is roughly the upper limit for daily zinc intake ^[ ii ] . Consuming more zinc can lead to abdominal cramps, vomiting, diarrhea, severe headaches, nausea and a loss of appetite.

Long-term supplementation with heavily dosed zinc supplements (which provide several tens of milligrams of zinc per day) increases the risk of prostate cancer according to several epidemiological studies ^[ iii ] .

DO ATHLETES NEED MORE ZINC?

There are at least two reasons why athletes in general are likely to need more zinc than the above recommendation:

• Exercising often means sweating a lot and when you sweat, you lose minerals such as magnesium and zinc;
• During strenuous exercise, micro-cracks appear in the muscles. To fix them, athletes typically require higher amounts of most vitamins and minerals — including zinc — than non-athletes ^[ iv ] .

If you, as an athlete, get too little zinc, this can have adverse consequences:

• It undermines the flexibility of the red blood cells during physical exertion, which
  can reduce blood flow to the muscles ^[ iv ] ;
• It can lower testosterone levels, which is especially detrimental if you already have low testosterone levels ^[ v ] ;
• It may mean decreased insulin sensitivity ^{[ vi ] [ vii ]} , resulting in decreased glucose uptake by muscle cells and increased blood glucose levels. This in turn can be at the expense of the available energy for sports performance;
• It can make you sick more quickly. Zinc is essential to keep the immune system strong.

BODYBUILDERS

The foregoing suggests that strength athletes, such as bodybuilders, also need more zinc than the average person. This is not so much because of the sweating, because with most forms of strength training (except metabolic) you do not sweat that much. This is because of the role that zinc plays in building proteins and in the growth and renewal of tissue. From that role, the mineral also contributes to muscle recovery and growth. Zinc speeds up muscle-building chemical reactions in your body, stabilizes protein structures and helps regulate hormone levels ^[ viii ] . These functions aid the muscle protein synthesis process initiated by strength training ^[ ix ] .

Zinc also contributes to a certain extent to the maintenance of muscle mass. As an antioxidant, zinc works in your body to prevent the breakdown of cells as a result of free radicals. By neutralizing the effects of free radicals, zinc may help slow the aging process and associated muscle loss ^[ viii ] .

It is not known how much more zinc athletes, bodybuilders in particular, need. There is simply no direct research into this.

DO YOU NEED A ZINC SUPPLEMENT AS A BODYBUILDER?

We saw that as a bodybuilder you probably need more zinc than the recommended 9 mg per day (for men). But that doesn’t mean you have to start taking zinc tablets right away. After all, it is plausible that most bodybuilders already get more than enough zinc through their diet. For muscle growth, you need to maintain a calorie surplus, ranging from 10 to 20 percent of your maintenance level (“bulking“). The extra food you eat as a result, roughly 500 kcal per day, also contains zinc, especially if you consume a lot of meat, dairy and eggs – typical bodybuilders food. You probably get enough zinc even without that surplus.

Still, there are situations where zinc supplementation can be helpful:

• if you are vegetarian or vegan and your daily diet may contain too little zinc;
• if you exercise intensively and also have a calorie-restricted diet, such as cutting with bodybuilders.

In short, in the bulk you normally do not need zinc from a jar. Possibly in the cut, especially if you also do cardio in addition to strength training. Many bodybuilders eat healthier than normal during the cut, but with a prolonged cut, the calorie intake will have to decrease further and further due to the slowing metabolism. With a large calorie deficit in combination with intensive exercise, a shortage of certain micronutrients is realistic.

You don’t necessarily have to buy a separate zinc supplement though. Zinc is almost always in multivitamin supplements.

ZINC AS A TESTOSTERONE BOOSTER?

Zinc is also used by bodybuilders as a testosterone booster. And indeed, zinc supplementation can increase testosterone levels, according to a number of human studies. But in those studies there were always rather specific situations:

• men on hemodialysis who are zinc deficient and have sexual problems ^[ xi ] ;
• athletes (in this case wrestlers) with reduced testosterone levels as a result of an exhausting training scedule ^[ xii ] ;
• men with a sedentary lifestyle who follow an intensive cycling training for four weeks – effect of zinc supplementation again on reduced testosterone levels as a result of exercise ^[ xiii ] ;
• infertile men with low testosterone levels – effect only at testosterone levels below a certain threshold (4.8ng/mL) ^[ xiv ] .

In short, zinc supplementation only seems to make sense if testosterone levels are severely reduced, for example in infertile men or as a result of very intensive exercise.

Translating this to the bodybuilder, extra zinc intake only during prolonged cutting could be a useful strategy. After all, during a calorie-restricted diet, your testosterone level drops, both due to the calorie restriction and the decrease in your body percentage.

Less testosterone does not mean immediate loss of muscle mass. As long as your testosterone levels remain within the natural range, there is actually no direct anabolic or catabolic effect when those levels go up or down. However, your testosterone level may influence your energy and therefore also your training performance.

IGF-1

Zinc also influences the production of IGF-1 (insulin-like growth factor), a substance produced by the growth hormone HGH and which plays an important role in muscle growth. But here too, zinc only increases IGF-1 concentrations in people who are zinc deficient ^[ xv ] .

WHICH ZINC SUPPLEMENT TO BUY?

If you are going to buy a zinc supplement, you will notice that there are different forms of zinc on offer.

Some of these serve a specific health purpose. For example, zinc gluconate and zinc acetate are used in the fight against the common cold and often added to lozenges and sprays. Zinc sulfate is specifically used for acne reduction.

While zinc sulfate is the most affordable, it is also the most difficult to absorb and can cause side effects such as upset stomach ^[ xvi ] .

The most common forms of zinc are zinc orotate and zinc citrate, both of which are well absorbed by the body ^[ xvii ] . Citrate has a slightly less bitter taste. Zinc picolinate is also often used for supplements. This form of zinc is said to be absorbed by the body even better than gluconate and citrate ^[ xviii ] .

The vast majority of zinc supplements are offered in tablet or capsule form. The recommended adult dose is 15 to 30 milligrams of zinc per day ^{[ xix ][ x ]} .

You don’t necessarily have to buy a separate zinc supplement. Zinc is almost always in multivitamin supplements, but often in a smaller dose, for example 5 milligrams.

Among bodybuilders, ZMA, a combination of zinc, magnesium and vitamin B6, is popular. In principle a great option if you want to supplement all three substances. Typically, one dose provides around 10 mg of zinc and 150 milligrams of magnesium. ZMA is also often touted as a testosterone booster, but there isn’t enough scientific research to back up that claim.

ZINC AND COPPER

The amount of zinc you ingest daily also affects another trace element, namely copper. Copper is involved in the formation of connective tissue and bones. It also ensures the formation of pigment in the hair and a proper functioning of the immune system. Copper is found in vegetables, fruit, meat, bread and other grain products, and cocoa products.

The absorption of copper is inhibited by vitamin C, iron and zinc, when you consume them in excess. Something that is possible when you use supplements. You may be taking a zinc tablet every day while consuming plenty of zinc through your diet, even as an athlete. For that reason, some copper is often added to zinc supplements. This way you can be sure that your zinc intake will not disturb the absorption of copper. Take a zinc supplement with copper if you plan to take a high dose or if you are not sure if you are zinc deficient.

IN SUMMARY

1.    Zinc is an important mineral that is involved in, among other things, the construction of proteins, the growth and development of tissue, and the proper functioning of the immune system.

2.    You should get about 10 mg of zinc every day. Normally this can be done without any problems through food. Zinc is found in small amounts in many different foods, such as meat, dairy products, grain products, nuts and shellfish such as shrimp and mussels. A zinc deficiency or surplus is rare.

3.    Athletes usually need a little more zinc than non-athletes. This is because they sweat out zinc and because extra zinc is needed to facilitate repair of muscle damage.

4.    Bodybuilders especially need extra zinc because of the role that zinc plays in muscle protein synthesis and thus in muscle repair and growth. In addition, zinc has a protective function for existing muscle mass.

5.    With a normal diet and especially in bulk, you as a bodybuilder probably get more than enough zinc. Zinc supplementation may be necessary during the cut, especially if there is a long-term energy deficit and/or a lot of cardio. Vegetarians and vegans also often need a zinc supplement.

6.    Zinc supplements only function as a testosterone booster in cases of zinc deficiency and/or unusually low testosterone levels. With sufficient zinc and normal testosterone levels, there is probably no appreciable effect.

7.    The recommended dose of zinc supplements for adults is 15 to 30 milligrams per day. The upper limit for total zinc intake is 40 milligrams per day.

8.    The absorption of another important mineral, copper, is inhibited by, among other things, zinc, if you consume it in excess. Take a zinc supplement with copper if you plan to take a high dose or if you are not sure if you are zinc deficient.

REFERENCES

• ^[ i ] https://www.voedingscentrum.nl/encyclopedie/zink.aspx
• ^[ ii ] https://healthyeating.sfgate.com/much-zinc-much-humans-5684.html
• ^[ iii ] https://www.oncoline.nl/index.php?pagina=/guideline/item/pagina.php&id=40202&guideline_id=1017
• ^[ iv ] https://www.uofmhealth.org/health-library/hn-3902000
• ^[ v ] https://examine.com/rubric/effects/view/37dec9b89cf28a70e10d1ba1fa2f9c09/d7cb526b5896d0051a93a131651574ce/all/
• ^[ vi ] http://www.ncbi.nlm.nih.gov/pubmed/21028969
• ^[ vii ] http://www.ncbi.nlm.nih.gov/pubmed/20045801
• ^[ viii ] https://www.livestrong.com/article/487452-do-zinc-supplements-help-build-muscle/
• ^[ ix ] https://www.ncbi.nlm.nih.gov/pubmed/2432920
• ^[ x ] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3724376/
• ^[ xi ] http://www.ncbi.nlm.nih.gov/pubmed/20446777
• ^[ xii ] http://www.ncbi.nlm.nih.gov/pubmed/16648789
• ^[ xiii ] http://www.ncbi.nlm.nih.gov/pubmed/17984944
• ^[ xiv ] http://www.ncbi.nlm.nih.gov/pubmed/7271365
• ^[ xv ] https://examine.com/rubric/effects/view/37dec9b89cf28a70e10d1ba1fa2f9c09/cda7de7794b6237ad733993d90b080b4/all/
• ^[ xvi ] https://www.livestrong.com/article/409076-which-form-of-zinc-is-best/
• ^[ xvii ] https://www.ncbi.nlm.nih.gov/pubmed/24259556
• ^[ xviii ] https://www.ncbi.nlm.nih.gov/pubmed/3630857
• ^[ xix ] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4120804/