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If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
There’s a very real infertility crisis going on in the United States––and not just for women. As of 2013, over 9% of American men aged 15-44 had experienced fertility problems (Chandra, 2013).
And a study of 43,000 men from North America, Europe, Australia, and New Zealand found that sperm counts per milliliter of semen dropped by nearly 60% between 1973 and 2011. Even if you’re not thinking of kids yet, you should care about your sperm health, which could be as easy as preventing zinc deficiency (Levine, 2017).
Zinc is a mineral that’s crucial to your body in many ways. Although only trace amounts are needed (the recommended dietary allowance is 11 mg per day for adult men and 8 mg for adult women), this micronutrient helps keep your body functioning properly.
It plays a key role in wound healing and immune function, cell division, and the formation of DNA and proteins. It’s also vital for growth and development and influences taste and smell, and can potentially slow age-related macular degeneration.
Symptoms of zinc deficiency
A zinc deficiency can be hard to diagnose, which is why you need to know the signs and symptoms.
Since some of them are nonspecific (meaning many conditions could cause the same symptoms), it will help your healthcare practitioner if you can recognize and describe your experience.
Here are eight common signs your zinc levels might be too low.
1. Loss of appetite
Dr. Dana Hunnes, a senior dietitian at Ronald Reagan UCLA Medical Center, says losing your appetite is a telltale sign of low zinc. While medical professionals often see patients with a diminished appetite, studies tend to go in the other direction.
One study showed zinc supplements successfully boosted calorie intake in patients with anorexia. More studies need to be done to clarify zinc’s role in the body, but it’s believed it influences appetite by affecting a hormone called ghrelin. Sometimes referred to as “the hunger hormone,” ghrelin stimulates appetite, increases food intake, and promotes fat storage (Suzuki, 2011; Khademian, 2014).
2. Weakened immune system
Even mildly low zinc levels can have an impact on immune function. A meta-analysis showed zinc supports your immune system enough that supplementing with it can reduce the duration and severity of the common cold––as long as it’s taken early (Prasad, 2008).
Preliminary work seems to show that lozenges made of zinc gluconate are as effective as zinc acetate (another common form of zinc used to treat deficiencies).
So instead of agonizing over the decision at the drugstore, you can simply pick one and start your supplement regimen. Just be careful with zinc nasal sprays as people have reported dulled sense of smell as a side effect (Hemilä, 2017).
3. Weight loss
Low zinc is also known for causing weight loss. It manipulates levels of ghrelin and leptin (the satiety hormones) in your body. That’s why lower than ideal zinc levels can leave you without an appetite and as a result, unintentional weight loss.
Unfortunately, you’ll need to watch for diarrhea on either side of your zinc intake. Taking too much can cause this unpleasant symptom, as well as having a deficiency. Diarrhea can also make a deficiency in this crucial mineral worse because it prevents proper absorption.
That’s also serious because zinc is essential for immune response to gut issues that could potentially cause loose stool. So if you know you’re deficient (even if you’re already on a treatment plan) and have had diarrhea for several days, it’s time to call your healthcare provider.
5. Inability to heal wounds
It’s difficult to overstate how vital this mineral is to this process. The role of zinc in wound healing is multi-dimensional, and getting the right amount allows for every step of this process to happen (Lin, 2017).
Elemental zinc is required for coagulation (blood clotting at the wound site), immune defense where you were hurt, and skin cell repair. Zinc is also vital to forming scars and synthesizing protein and collagen.
6. Dulled sense of taste or smell
Older adults are especially prone to losing their sense of taste and smell if they’re not getting adequate zinc.
In America, deficiencies may not be too common, but it’s estimated that 20–25% of adults ages 60 and older don’t get enough zinc––even after supplements are counted (Pisano, 2016).
7. Hair loss
Hair loss, or alopecia, is an extremely common sign of zinc deficiency, although not everyone with low zinc will develop it.
Luckily, it seems like hair loss from this can be reversed or alleviated by bringing up zinc levels in the blood. In one small study, hair loss slowed or was cured by zinc supplementation in people who were deficient and suffering from alopecia (Karashima, 2012; Saper, 2009).
In another study, 9 out of 15 patients saw an improvement, although researchers say this isn’t significant enough to make conclusions because of the small study size. More work needs to be done, but dietary zinc can be an easy and safe way to bring up low numbers and potentially slow or stop hair loss (Park, 2009).
Our daily zinc needs are relatively low, but they increase for pregnant women. Zinc is vital for proper growth and development for babies in the womb, and low zinc can cause growth retardation. This is especially pronounced in the reproductive system, in which a zinc deficiency can cause arrested puberty.
One example of this is Prasad Syndrome, which is caused by iron and zinc deficiencies. Signs of this include skin changes, anemia (a lack of red blood cells), and hypogonadism (when sex glands produce little or no sex hormones), among other symptoms.
Although all of these can be signs of a zinc deficiency, it’s important to note that not everyone’s experience will be the same. You could have these symptoms if your blood zinc levels get too low, or you may not. You may have other symptoms altogether, as everyone’s body shows signs a little differently.
Who is at risk for zinc deficiency?
There are several groups of people who have a higher chance of becoming zinc deficient.
In the United States, infants breastfeeding and older adults have the highest risk. Pregnant women can easily experience low zinc since their needs go up as their baby develops.
Alcoholics are also at greater risk due to malabsorption. Chronic diseases that affect zinc absorption are also risk factors, including liver disease, Crohn’s disease, and sickle cell disease.
People with acrodermatitis enteropathica, a rare genetic disorder that binds zinc, have many symptoms that align with a zinc deficiency including alopecia, dermatitis, and diarrhea. Those taking proton pump inhibitors to reduce stomach acid may also suffer from low zinc levels since these medications interfere with absorption.
Diagnosing zinc deficiency
Zinc is distributed throughout the cells of your body in very small amounts, so medical professions may need to use more than one test to see if you’re low.
There are a few tests professionals can try, though none are 100% accurate. You may show normal zinc levels on your test even if you’re actually deficient. You can get a plasma test, which is taken from your blood plasma (the yellowish liquid component of blood). There are also urine tests and hair analysis that also test for zinc.
Once your diagnosis is confirmed, they’ll work with you on getting to the root of the problem. It’s relatively easy to get enough zinc through our dietary intake, so if your serum zinc is low, it may be a symptom of an underlying condition.
Treatments for low zinc
The plan for treating low serum zinc levels depends on how bad the deficiency is.
“At the hospital, we either give IV push zinc or recommend 220 mg zinc sulfate daily for 14 days,” Dr. Hunnes explains.
Patients will start to feel better quite quickly, though. “Depending on how severe the deficiency is, it may take a few days to fix,” she says. “But since we don’t really store zinc, it’s usually a quick turnaround.”
In cases of a severe deficiency, improving zinc status may require high-dose supplementation. Unfortunately, not all the symptoms go away as quickly as the numbers rebound, like hair growth.
Supplements and dietary zinc
If you’re going to use supplements, always follow medical advice because having too much zinc can be dangerous.
To prevent low levels, a medical professional may advise you to take a multivitamin, which generally contains the mineral. Oral zinc is also available on its own.
You may not need to supplement though, since the recommended daily allowance is relatively easy to hit for omnivores. The dietary reference intake guidelines limit daily zinc intake to 40 mg, a number based on when zinc starts to interact negatively with copper levels (Inst. of Medicine, 2001).
Adding red meat, poultry, and oysters to your diet can significantly boost your zinc intake to hit the recommended dietary allowance. Whole grains also contain zinc, although some (like oats) contain phytic acid, a compound found in bran and seeds that hinders zinc absorption.
One way around this is choosing fortified breakfast cereals made with whole grains to boost dietary intake. Fortification appears to sidestep this interaction that causes malabsorption. Vegans and vegetarians can lean on legumes such as peanuts, chickpeas, and beans since they have a solid amount of zinc.
- Chandra, A., Copen, C. E., & Stephen, E. H. (2013). Infertility and Impaired Fecundity in the United States, 1982–2010: Data From the National Survey of Family Growth (pp. 1–19). Hyattsville, MD: National Center for Health Statistics. Retrieved from https://pubmed.ncbi.nlm.nih.gov/24988820/
- 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), 2054270417694291. doi: 10.1177/2054270417694291. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28515951/
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- National Institutes of Health: Office of Dietary Supplements. (2019, July 10). Zinc: Fact Sheet for Health Professionals. Retrieved from https://ods.od.nih.gov/factsheets/zinc-HealthProfessional/
- Park, H., Kim, C. W., Kim, S. S., & Park, C. W. (2009). The Therapeutic Effect and the Changed Serum Zinc Level after Zinc Supplementation in Alopecia Areata Patients Who Had a Low Serum Zinc Level. Annals of Dermatology, 21(2), 142–146. doi: 10.5021/ad.2009.21.2.142. Retrieved from https://pubmed.ncbi.nlm.nih.gov/20523772/
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Dr. Mike is a licensed physician and the Director, Medical Content & Education at Ro.