Zinc is an essential mineral that helps perform a variety of tasks in the human body: from analyzing quantum physics questions to performing even the most minute tasks, such as lifting a finger (1).
After iron, zinc is the most abundant trace mineral in the body and is involved in the catalytic activity of more than 300 enzymes involved in the synthesis and metabolism of carbohydrates, fats, proteins, and other micronutrients (2, 3, 4).
Zinc also plays roles in stabilizing cell and organ structures, immune function, wound healing, cell division, growth, blood clotting, thyroid function, vision, taste, and smell. Despite its critical role in humans, zinc is not stored in the body and must be gotten through our diet (5, 6).
Zinc is essential for the proper function of our immune system. Due to it’s importance, studies dating back as far as 1990 show that even a mild deficiency can impair immune function and increase the risk of bacterial, viral, and parasitic infection (7, 8).
Zinc acts as an antioxidant. A 1997 study published in the Journal of Clinical Nutrition showed that zinc supplementation was able to reduce fat peroxides in the blood (9).
Another 2011 study demonstrated that zinc acts as an anti-inflammatory agent by inhibiting the production of many inflammatory cytokines (10).
Zinc has also been linked to a decreased risk for a number of diseases, due to its role in the growth and repair of cells. A 2011 study performed by the Health Research Institute found that people suffering from Autism tend to have lower levels of zinc than non-autistic individuals. In the study, the severity of autistic symptoms decreased after patients were treated with zinc (23).
Zinc can improve the function of killer cells to wipe out tumours and prevent cancer.
A study published in 2012 showed that low levels of zinc are associated with head, neck, lung, gall bladder, prostate, and ovarian cancers (26).
Zinc may also be a treatment for epileptic seizures. A 2015 study in epileptic children, published in Functional Neurology, revealed that zinc therapy significantly reduced the frequency of seizures in 31% of the treated children (30).
Zinc plays an important role in heart health. Two 2013 studies showed that zinc levels are often low in people with atherosclerosis (hardening of the arteries), heart disease, chest pain, and heat stroke, and another study found that a higher rate of cardiac failure was associated with zinc deficiency (31, 32, 33, 34).
Zinc is important for proper hormone function, including insulin. To that end, zinc plays a vital role in the treatment of diabetes. Zinc binds to insulin receptors, and by mimicking insulin, it reduces excessive insulin secretion by pancreatic cells and helps protect the pancreatic tissue from damage (35, 36).
Zinc plays a vital role in brain function. Studies have shown zinc supplementation was able to enhance cognitive recovery in zinc-deficient stroke victims (41).
One study in particular out of Canada observed in children found that zinc supplementation resulted in superior neuropsychological performance, particularly attention and reasoning skills. While a randomized trial showed that zinc supplementation in infants and toddlers led to increased activity, mental development and motor quality (42, 43, 44, 45,).
A 2014 study in elderly patients with Alzheimer’s, showed that zinc therapy protected against cognitive decline by lowering free blood copper levels, which can be toxic to the brain (46).
It also increases brain-derived neurotrophic factor levels, which are low in people with depression.
Zinc also plays a major role in male reproductive health. In men, zinc plays a key role in sperm count, motility, and viability (53, 54, 55). Low to moderate doses (12 -120 mg/kg) of zinc intake appeared to enhance reproductive function in rats.
Zinc is also involved in the synthesis of testosterone and in infertile men (with low blood testosterone), supplementing with zinc led to an increase in sperm count, testosterone, dihydrotestosterone (DHT), and fertility (56, 57, 58).
Zinc also plays a major role in women’s hormonal health. Zinc deficiency is associated with hormonal imbalances that can lead to ovarian function problems, menstruation irregularities, and infertility (62).
In women with polycystic ovarian syndrome (PCOS), insulin resistance can cause increased production of androgen hormones (e.g., testosterone and DHEA), which can lead to balding, body hair growth, irregular periods and infertility (63).
Zinc also plays a role in how we look. Zinc affects the hormone, Leptin – which plays a role in appetite and weight control. Zinc restriction can lead to reduced leptin production from fat cells in rats and humans (71, 72, 73, 74).
Too much zinc can harm the immune system. A study in healthy young men gave them 150mg of zinc supplementation, twice per day, for six weeks. What they found was that high doses of zinc reduced several immune functions, including activation of lymphocytes and phagocytosis of neutrophils (84).
Oral zinc can cause IBS like symptoms. These include indigestion, diarrhea, headache, stomach pains, nausea, and vomiting. Zinc applied directly to open wounds can also cause itching, burning, and stinging.
Zinc nasal spray can cause loss of smell. In June 2009, the US Food and Drug Administration advised consumers not to use certain zinc-containing nose sprays after receiving over 100 reports of loss of smell.
Additionally, when taken long-term, zinc can cause copper deficiency. People with low copper levels might experience neurological issues, such as numbness and weakness in the arms and legs.
Zinc has two standard dosages. The low dosage is 5-10 mg, while the high dosage is 25-45mg.
The low dose works well as a daily preventative, while the high dosage should be taken by anyone at risk for a zinc deficiency.
Good dietary sources of zinc include red meats, seafood, dairy products, nuts, legumes, and whole grains (85).
However, zinc is more readily absorbed from meat and animal proteins. Vegetables are not ideal sources because they contain phytate, a compound in plants that prevents zinc from being absorbed (86).
What is zinc and where does it come from?
Zinc is classified as an essential mineral, and with good reason. It is essential to over 180 biologic functions. Many foods rich in trace minerals contain zinc, with the highest amounts in meat products. Lesser amounts are found in milk, spinach, nuts, oats, rice, and beans. Rice and beans are high in phytates which compete with zinc for bioavailability, thus not as good of a source as animal products or nuts and beans.
Who needs it and what are the symptoms of deficiency?
Many experts say that zinc deficiency is widespread. People living in poverty with diets low in zinc, especially children below five years of age, need zinc the most. Deficiencies result in poor wound healing because of zinc’s role in cellular repair. Zinc deficiency also leads to slower growth. Most importantly, children with low levels of zinc are at increased risk for infection, severe infections, and death.
What are the additional benefits of zinc?
Zinc is beneficial in treating diarrhea and slow growth in children, vital for healthy skin and helps to reduce problems such as acne, controls sleep disorders and is regarded as an excellent sleep promoter, and helps to fight bad breath.
What are good natural food sources of zinc?
The best sources include pumpkin, pumpkin seeds, sesame seeds, soybeans, peas, green beans, sprouts, spinach, corn, kidney beans, watermelon seeds, garlic, potatoes, fortified cereals, milk, brown rice, pomegranates, avocados, blackberries, raspberries, beef, egg yolk, lobster, pork, lamb, crab, oysters and shrimp.
What are the symptoms of Zinc deficiency?
Symptoms of zinc deficiency include acne, skin rashes, hair thinning (Alopecia), repeated diarrhea, lack of appetite, dry skin, vision issue, stunted or slowed growth, weight loss, slow wound healing and a poor sense of smell or taste.
Which population is at the highest risk of zinc deficiency?
People with the highest risk for a zinc deficiency include alcoholics, those with gastrointestinal issues, liver disorders, diabetes, kidney disease, or those suffering from Crohn’s or Sickle Cell disease.
Does zinc boost testosterone?
Zinc is an aphrodisiac and testosterone booster, but it will only help raise testosterone levels if you’re deficient in zinc. It will also aid in raising libido and erection quality.
Does zinc interact with any medications?
Zinc has significant interactions with a few different medications: Cephalexin and Penicillamine.
Cephalexin is used to treat infections and can have its effectiveness reduced when taken within three hours after taking zinc. Penicillamine is used to treat Wilson’s disease and rheumatoid arthritis, and when taken within 2 hours of taking zinc, can have its rate of absorption reduced.
Zinc also has a moderate reaction with a few different antibiotics, so you should always consult with your doctor if you are supplementing with zinc.
Can you take zinc with other supplements?
Always consult your doctor when combining supplements. For example, taking zinc and vitamin C at the same time could cause digestive discomfort. Iron also inhibits zinc absorption, so if you’re also taking iron, it may be best to supplement the two at different times.
Zinc is one of the most important minerals in the human body. It’s involved in everything from treating and preventing certain diseases, improving sexual health, fighting off depression and much more. Moreover, while rare, side effects from zinc are still possible. Therefore you should always consult your doctor before beginning a supplementation regimen.
Zinc can be gotten from food, so as long as they are included in a healthy diet, real food should be your first source of zinc. However, to avoid a potential deficiency, regular supplementation may be a good idea. As always, consult your doctor.