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Zinc is an essential micronutrient that your body needs in order to function properly. Your body can’t make zinc so you must get it from food or supplements.
Below, we’ll walk you through everything you need to know about zinc including how it helps your body stay healthy and how much you need for optimal health.
What is zinc?
Zinc is a trace mineral, meaning that you only need a small amount of it per day. The only catch is your body can’t make zinc on its own. Your body also doesn’t store this mineral, so you need to make sure you get enough daily through either food or zinc supplements.
What does zinc do for the body?
Zinc helps keep cells in your body functioning properly. For example, zinc plays a role in promoting enzyme function. This helps your body do things like break down carbohydrates, secrete insulin, and maintains your sense of taste and smell (Morris, 2021).
Zinc is also crucial for skin health, immune function, cell growth, and wound healing (Rabinovich, 2021).
Health benefits of zinc
Zinc has a multitude of health benefits. Here is an overview of the main ones.
Supports immune function
Zinc is essential to maintaining white blood cells. Studies suggest that zinc supplements may improve your ability to fight off infections like the common cold (Wessels, 2017).
One study found that oral zinc supplements or dietary zinc helped people get over a cold 30% faster, especially when taken at the first sign of cold symptoms (Hemilä, 2017).
However, if those sniffles are due to COVID-19, research shows zinc may not do much. One clinical trial found that the use of high-dose zinc supplements didn’t shorten how long people experienced COVID symptoms (Thomas, 2021).
The use of zinc can be a short-term solution for treating diarrhea in children, mostly in developing countries. The recommended dose is 20 mg daily for adolescents and 10 mg for babies younger than six months (NIH, 2021).
Another recent study found that lower levels of zinc for kids still effectively treated diarrhea and reduced the chance of vomiting or upset stomach (Dhingra, 2020).
Helps with fertility
Zinc intake may play a role in promoting fertility in both men and women. Studies looking specifically at zinc’s effects on testosterone are limited, but some show that low zinc can interfere with testosterone levels, which are needed for healthy sperm production (Fallah, 2018; Terrin, 2015).
Signs of infertility in men and women
Delays vision loss
A review of studies found that antioxidants like zinc play a role in preventing age-related macular degeneration, an eye disease that causes vision loss.
Studies have found that supplementing with antioxidants may halt the progression of the condition, though more research is needed to determine if long-term supplementation of certain antioxidants is harmful (Evans, 2006).
Sources of zinc: food and supplements
There are two main sources of zinc: food and supplements. Most people will be able to get enough of this mineral through diet alone.
Foods high in zinc
The National Institutes of Health (NIH) lists there are many foods that are good sources of zinc including (NIH, 2021):
- Shellfish: Oysters, crab, and lobster
- Fish: Flounder and sole
- Meat: Beef and pork
- Poultry: Chicken and turkey
- Legumes: Peas, kidney beans, baked beans, and chickpeas
- Nuts and seeds: Pumpkin seeds, cashews, and almonds
- Dairy: Yogurt, milk, and cheddar or mozzarella cheese
- Whole grains: Bran and wheat germ
- Fortified foods: Oatmeal and some breakfast cereals
In addition to your dietary intake, you can also take zinc supplements. If you don’t have a zinc deficiency taking supplements won’t hurt you (as long as you don’t swallow too many––more on that below), but the jury is still out if you’ll actually benefit from them.
When shopping around, you may see different forms of elemental zinc like zinc gluconate, zinc acetate, and zinc sulfate. Zinc gluconate and acetate are typically found in cold medications like nasal sprays (Hunter, 2021). Zinc sulfate is beneficial for topical formulations for treating skin conditions like acne (Cervantes, 2017).
Just be mindful that this trace element can inhibit copper absorption (which your body also needs) and supplementing can accidentally create a copper deficiency (NIH, 2021).
Zinc and testosterone: what’s the connection?
How much zinc do I need per day?
The amount of zinc your body needs varies based on factors like age and if you’re pregnant or nursing.
The general recommended dietary allowance (RDA) is 8 mg for adult females and 11 mg for adult males. Pregnant women should get about 11 mg and lactating mothers require roughly 12 mg of zinc daily (NIH, 2021).
The tolerable upper level—or maximum amount considered safe—is 40 mg per day for healthy adults. This, however, is not the case for someone with a zinc deficiency (NIH, 2021).
Signs of a zinc deficiency
In North America, zinc deficiencies are uncommon but not totally unheard of. Certain groups of people are also at higher risk for developing zinc deficiency than others.
In mild cases, signs of a zinc deficiency include loss of appetite and low immune function. In more severe cases, symptoms can cause hair loss, diarrhea, impotence, and eye or skin lesions (NIH, 2021).
Those most at risk for a zinc deficiency include pregnant women, vegetarians, and those with gastrointestinal or digestive problems that inhibit zinc absorption (NIH, 2021).
Just like too little can cause problems, too much zinc can also lead to side effects. This mostly pertains to supplemental zinc––there’s not much evidence that people overdose on zinc from food sources. Symptoms of zinc toxicity include (Bartzatt, 2017):
- Problems breathing
Getting enough zinc? These 7 foods are packed with it
Although zinc is considered relatively non-toxic, it’s important to not overdo it and follow any medical advice while taking supplements (Bartzatt, 2017).
If you want to use zinc nasal sprays, make sure to talk to a healthcare provider first. In 2009, the U.S. Food and Drug Administration (FDA) advised against using three zinc-containing nasal sprays because they were linked to temporary loss of sense of smell (NIH, 2021).
Zinc: the takeaway
Your body needs zinc to function properly and support your immune system. It also interacts with other important vitamins and minerals like calcium, vitamin A, and vitamin C. You should be able to get enough daily by consuming some of the foods listed above. Before taking any dietary supplements like zinc, consider talking to a healthcare professional first.
- Bartzatt, R. (2017). Neurological impact of zinc excess and deficiency in vivo. European Journal of Nutrition & Food Safety, 7(3), 155-160. doi:10.9734/ejnfs/2017/35783. Retrieved from https://www.researchgate.net/profile/Ronald-Bartzatt/publication/319200315_Neurological_Impact_of_Zinc_Excess_and_Deficiency_In_vivo/links/599c8eb6aca272dff12bbf11/Neurological-Impact-of-Zinc-Excess-and-Deficiency-In-vivo.pdf
- Cervantes, J., Eber, A. E., Perper, M., et al. (2018). The role of zinc in the treatment of acne: A review of the literature. Dermatologic Therapy, 31(1). doi:10.1111/dth.12576. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29193602/
- Dhingra, U., Kisenge, R., Sudfeld, C. R., et al. (2020). Lower-dose zinc for childhood diarrhea—A randomized, multicenter trial. New England Journal of Medicine, 383(13), 1231-1241. doi:10.1056/nejmoa1915905. Retrieved from https://www.nejm.org/doi/full/10.1056/NEJMoa1915905#:~:text=The%20zinc%20recommendation%20is%20based,illness%20and%20increase%20weight%20gain
- Evans, J. R. (2006). Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. The Cochrane Database of Systematic Reviews, 2, CD000254. doi:10.1002/14651858.CD000254.pub2. Retrieved from https://pubmed.ncbi.nlm.nih.gov/16625532/
- Fallah, A., Mohammad-Hasani, A. & Hosseinzadeh Colagar, A. (2018). Zinc is an Essential Element for Male Fertility: A Review of Zn Roles in Men’s Health, Germination, Sperm Quality, and Fertilization. Journal of Reproduction & Infertility, 19(2):69-81. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010824/
- Hemilä, H. (2017). Zinc lozenges and the common cold: A meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. JRSM Open, 8(5), 205427041769429. doi:10.1177/2054270417694291. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28515951/
- Hunter, J., Arentz, S., Goldenberg, J., et al. (2021). Zinc for the prevention or treatment of acute viral respiratory tract infections in adults: a rapid systematic review and meta-analysis of randomised controlled trials. BMJ Open, 11(11), e047474. doi:10.1136/bmjopen-2020-047474. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8578211/
- Marreiro, D., Cruz, K., Morais, J., et al. (2017). Zinc and oxidative stress: Current mechanisms. Antioxidants, 6(2), 24. doi:10.3390/antiox6020024. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28353636/
- Morris, A. L. & Mohiuddin, S. S. (2021). Biochemistry. Nutrients. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK554545/
- National Institutes of Health (NIH). (2021). Zinc. Retrieved from https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/
- Rabinovich, D. & Smadi, Y. (2021). Zinc. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK547698/
- Terrin, G., Berni Canani, R., Di Chiara, M., et al. (2015). Zinc in early life: A key element in the fetus and preterm neonate. Nutrients, 7(12), 10427-10446. doi:10.3390/nu7125542. Retrieved from https://pubmed.ncbi.nlm.nih.gov/26690476/
- Thomas, S., Patel, D., Bittel, B., et al. (2021). Effect of high-dose zinc and ascorbic acid supplementation vs usual care on symptom length and reduction among ambulatory patients with SARS-Cov-2 infection. JAMA Network Open, 4(2), e210369. doi:10.1001/jamanetworkopen.2021.0369. Retrieved from https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776305
- Wessels, I., Maywald, M., & Rink, L. (2017). Zinc as a gatekeeper of immune function. Nutrients, 9(12), 1286. doi:10.3390/nu9121286. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29186856/
Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.