The recommended dietary allowance for adult women is 8 milligrams (mg) per day and 11 mg for men, according to the National Institutes of Health (NIH). That amount can come from zinc-rich foods, such as oysters, red meat, crab, and lobster, or from supplements. There is, however, some research that suggests taking zinc in higher doses in supplement form may offer certain benefits for certain individuals. Most of this evidence involves consuming zinc at much higher doses than you could realistically expect from food. Unless you’re downing a few oysters every day, it’d be difficult to take in more than 40 mg of zinc per day, says Trista Best, RD, MPH, an environmental health specialist and consultant with Balance One Supplements (a company that sells supplements) based in Dalton, Georgia. Summer Yule, RD, a Hartford, Connecticut–based dietitian, recommends choosing whole foods over supplements if you can. “Supplements are more likely to interact with medications than foods,” she says. Those medications include antibiotics, immunosuppressant medications (like prednisone), ACE inhibitors (blood pressure medications, including benazepril [Lotensin], enalapril [Vasotec], and others), penicillamine (a drug used to treat rheumatoid arthritis), and diuretics, like chlorthalidone (Hygroton), amiloride (Midamor), and hydrochlorothiazide (Esidrix and HydroDiuril), according to Mount Sinai. “Additionally, supplements don’t always act in the body in the same way as a nutrient that is packaged in its natural food matrix,” Yule says. RELATED: Can a Supplement Protect Me Against the New Coronavirus? For all these reasons, don’t just start a supplement experiment on your own. Remember, supplements are not regulated by the U.S. Food and Drug Administration (FDA) before they are available on shelves, meaning the claims on their labels may or may not be based on reliable evidence (as with drugs). Supplements can also interact with other drugs or medications you’re taking in unintended ways. It’s always a good idea to discuss any supplements you might want to try with your healthcare provider, Yule says. Here are seven potential benefits that have been linked to zinc supplements.
1. Boosts the Immune System
Zinc is right up there with vitamin C as a popular cold remedy. “Immune cells depend on zinc for healthy development and function,” Best says. This role that zinc plays in immune functioning is why researchers suspect boosting zinc intake when you’re sick or just before you get sick may help shorten the duration of illness or help stop you from getting sick. According to a May 2017 meta-analysis published in JRSM Open, at least 75 mg of zinc per day shortened the common cold by 33 percent. Another meta-analysis, published in April 2017 Open Forum Infectious Disease found patients who took 80 to 92 mg of zinc per day to treat their cold recovered three times faster than those who did not, leading the study researchers to recommend that people take zinc acetate lozenges within 24 hours of experiencing symptoms. And while it’s too soon to know whether zinc can help people with COVID-19, there’s speculation that it might, especially those at high risk, according to a review published in July 2020 in Frontiers in Immunology. The NIH recommends 40 mg per day as the tolerable upper limit people should stick to, so it’s a good idea to check with your doctor for a personalized recommendation before trying a higher dose. RELATED: 7 Ways to Keep Your Immune System Healthy
2. Decreases Risk of Preterm Birth
Zinc helps the body make proteins and DNA, and it’s needed for proper growth and development, too, according to the NIH. Because of these functions it’s an important mineral for pregnant women and young children, and zinc supplements may help pregnant women avoid early labor. A review published in February 2015 in the Cochrane Database of Systematic Reviews found there was a 14 percent reduction in preterm birth when pregnant mothers took a zinc supplement. But the researchers noted that this could be because most of the studies they looked at involved low-income women who may have had poor overall dietary quality and been deficient in zinc to begin with. Therefore, the reduction in preterm birth may have been the result of the supplements correcting deficiencies rather than an added benefit of supplementation. Best says she’d only recommend a zinc supplement to a pregnant woman if she had a known deficiency. But for pregnant women and young children, it’s important to avoid deficiency by making sure you’re getting enough zinc in your diet. And it’s important to note that the recommended daily intake of zinc is increased for women who are pregnant to 11 mg per day for women 18 and older who are pregnant and 12 mg per day for those 14 to 18 years old who are pregnant.
3. Supports Childhood Growth
“Zinc deficiency in children can lead to failure to thrive, and zinc supplementation can help in some of these cases,” Yule says. According to a March 2018 meta-analysis published in Nutrients, zinc supplementation in infants and young children promoted healthy growth and led to increased height and weight, especially after the child’s second birthday. The researchers note, however, that the current evidence is still preliminary and more studies are needed to better determine which kids might benefit most from extra zinc. Zinc supplementation is still not necessary or recommended currently unless a deficiency is present, Yule says. And do talk with your child’s pediatrician about specific risks and potential benefits before starting your child on supplements.
4. Manages Blood Sugar
“Those with diabetes may be at higher risk for zinc inadequacy,” Yule says. A study published January–April 2020 in the Journal of Family and Community Medicine found 6.4 percent of participants in the control group were deficient in zinc, while 67.9 percent of participants from the group with diabetes were deficient, though the researchers couldn’t determine whether diabetes caused zinc deficiency or vice versa. “In some cases, these individuals will be able to meet their needs through diet, while others may benefit from supplementation,” Yule explains. According to a study published in Diabetology & Metabolic Syndrome, zinc supplementation contributed to blood sugar control and promoted healthy lipid parameters among people with diabetes. And supplementing with zinc has been shown to increase insulin sensitivity among obese individuals, in a study published in Biological Trace Element Research in April 2017. Zinc plays a role in the storage and secretion of insulin, the hormone that allows cells to use sugars from the food we eat so it doesn’t build up in the blood, explains Megan Wong, RD, a Vancouver-based nutritionist with AlgaeCal. Zinc supplementation isn’t part of standard diabetes treatment but could be worth asking your doctor about.
5. Slows the Progression of Macular Degeneration
This eye disease, which tends to worsen with age, can be treated with a few key vitamins and minerals, including zinc, according to the Cleveland Clinic. A systematic review published in Investigative Ophthalmology & Visual Science suggested that supplementation with a zinc-containing AREDS supplement (a specific type of multivitamin supplement) may prevent it from progressing, This may be because zinc plays a key role in retinal health or because older adults are more at risk of zinc deficiency, according to a study published in April 2019 in Antioxidants. NIH recommends consulting with your doctor to see if zinc supplementation should be part of your treatment plan.
6. Clears Up Acne
Zinc contains anti-inflammatory properties and also decreases oil production, which makes it a potential candidate for fighting acne, Best says. A study published in Dermatology found zinc led to improvements for patients with acne, but it wasn’t as successful as the acne treatment minocycline, a prescription antibiotic. Keep in mind that zinc’s acne-clearing abilities haven’t been studied as thoroughly as other treatments, such as salicylic acid and glycolic acid, so chances are your dermatologist will steer you toward a different, more effective ingredient first. And if you do want to try zinc, remember to still discuss with your doctor, as supplements may interact with other medications you’re taking. RELATED: Everything About Acne and How to Clear It Up
7. Promotes a Healthy Heart and Blood Vessels
An August 2015 systematic review and meta-analysis published in Nutrition & Metabolism found that supplementing with zinc (the studies included varying dosages from 15 to 240 mg per day) aided with a number of factors related to heart health, including lowering total cholesterol, low-density lipoprotein (LDL or “bad”) cholesterol, and triglycerides. A study published in Nutrition Research and Practice found a higher zinc intake was associated with lower systolic blood pressure readings among a group of 40 obese Korean women. The researchers weren’t sure why zinc has this effect, however. Best says that more research is always better, but on the basis of these studies, it does seem that zinc supplementation could help your heart. Be sure to consult your healthcare provider to get a recommendation that fits your health history.
