Thinning hair, stubborn acne, dandruff, wounds that take a long time to heal, always feeling rundown: You might overlook these as minor annoyances or blame them on aging or stress. But they may actually be signs that you’re suffering from low levels of zinc.
Often considered a go-to -support for helping kick the common cold, zinc does a whole lot more than bolster your immune system. Zinc is a trace element (meaning you require it only in small amounts), but it supports more than 300 functions in your body, including the creation of new cells after illness or injury. In fact, many functional-medicine practitioners are now looking to zinc to help address some common ailments, including gut dysfunction and mental health.
“Any system of the body that sees rapid cellular turnover uses zinc,” says Cindi Lockhart, RDN, LDN, national nutrition program manager at LT Proactive Care Clinic in St. Louis Park, Minn., noting that the immune system is an example of a cellular system that relies on zinc for regeneration. “And any growth and development stages of the life cycle, including pregnancy and early childhood, are times when zinc consumption is important. It’s a critical building block.”
GETTING YOUR DAILY ZINC
Like calcium and magnesium, zinc is an essential mineral, meaning your body can’t produce its own — it has to come from nutritional sources. Two to 3 grams of zinc is usually stored in your bones and muscles, but that’s not enough to do all of zinc’s jobs; that’s why you need to consume the mineral every day.
Zinc is widely available in the Western diet, and most American adults manage to get the recommended daily allowance (RDA) of 11 mg for men and 8 mg for women. Still, it’s not uncommon to be “marginally deficient,” says Teri Underwood, MS, RDN, CDN, a functional-medicine nutritionist in Park City, Utah.
Kathie Swift, MS, RDN, LDN, education director for Food As Medicine at the Center for Mind-Body Medicine and author of The Swift Diet, agrees. She notes that, while RDAs are helpful, “there is no one generic prescription for zinc.”
Vegetarians and vegans, for example, need to be especially mindful: Though zinc is widely found in grains and legumes, the body has a tough time absorbing it thanks to antinutrients in those plants called phytates. Zinc binds to these compounds, making the mineral less available to the body. (For more on antinutrients, see “All About Antinutrients“.)
Others at risk of deficiency include the elderly (as many as 45 percent of people over the age of 60 are low in zinc), alcoholics (alcohol depletes intestinal zinc absorption and increases zinc excretion through urine), people with gastrointestinal conditions, and pregnant or lactating women. Chronic dieting or a history of eating disorders can lead to suboptimal zinc levels, too.
Keep reading to learn how zinc supports everyday health — and how to make sure you get what you need.
ZINC IN ACTION
Zinc is necessary for many biological and cellular processes, and researchers are learning more all the time about how it supports overall health.
Zinc’s role in healing gut dysfunction is an emerging area of research, with many promising new findings. In a recent animal study at Cornell University, for example, researchers discovered that zinc deficiency alters the microbial population and diversity of the intestine — information that may have implications for a host of conditions affected by the gut’s bacterial profile.
Tammy Russell, MS, RDN, a functional-medicine specialist in Portland, Ore., recommends zinc for clients who have digestive problems, including acid reflux and irritable bowel syndrome. “Gut issues are epidemic in our society,” says Russell, who recommends that anyone diagnosed with gastrointestinal (GI) problems be tested for nutrient deficiencies by a trained nutrition professional.
The overgrowth of bad bacteria in the gut, which is often attributed to poor diet and antibiotics, can reduce the secretion of hydrochloric acid (HCl), which is required for proper digestion. In her practice, Russell has found that GI patients who supplement with 20 to 30 mg of zinc per day can help boost their system’s HCl production.
Zinc reduces cellular inflammation, protects immune-system lymphocytes (white blood cells), and prevents cellular oxidation. If you’re deficient in zinc, you’re more susceptible to pathogens and infections.
As for whether zinc supplements can ease a cold, research is promising but inconclusive. Try lozenges and syrup, and skip nasal sprays and gels, which can cause loss of smell.
FERTILITY AND PREGNANCY SUPPORT
Researchers don’t know exactly how zinc protects fertility, but there are obvious signs of the mineral’s importance: Men with low sperm counts have lower levels of zinc in their semen than men with higher sperm counts. Zinc can also help boost testosterone levels in otherwise-healthy males, which could lead to better sperm motility, and it seems to protect both eggs and sperm from the effects of oxidative stress and inflammation.
Because zinc protects the immune system, it appears to prevent the prenatal infections that can lead to pregnancy loss or preterm labor. Indeed, research has shown that adequate zinc levels in pregnant women decrease the risk of preterm births by as much as 14 percent, and women who go into preterm labor have been found to have lower concentrations of zinc in their blood than those who carry to term. Zinc is needed during embryogenesis to regulate chromosomal structures and gene expression, and the placenta needs zinc to establish cell regulation in the fetus.
About 6 percent of your body’s stored zinc can be found in the outer layer of skin (the epidermis) and in the underlying layers (the dermis). Zinc plays a key role in normal skin development and wound healing; in fact, deficiencies are often found in conjunction with skin disorders. In one study, patients with acne, psoriasis, and other skin conditions were found to have reduced zinc concentrations in their dermis and epidermis, despite normal serum zinc values. Research has also demonstrated that dietary zinc is effective in treating inflammatory acne.
MENTAL- AND EMOTIONAL-HEALTH PROTECTION
Zinc deficiencies are increasingly linked to poor mental health. While doctors have observed a correlation between depression and low zinc levels since the 1950s, a recent study published in PLOS ONE showed that almost one-third of all patients with depression, and half of patients with other psychiatric disorders, were zinc deficient. Researchers are currently investigating whether supplementing with zinc can be an adjunct treatment for major depressive disorder (MDD), especially when antidepressant therapies fail.
Researchers have paid particular attention to zinc concentrations in the brain’s hippocampus, which controls mood and memory. Because of its anti-inflammatory and immunity-boosting properties, some believe zinc protects the hippocampus from the negative effects of excessive stress and oxidation.
GET YOUR ZINC EVERY DAY
Zinc is found in a wide variety of foods, but studies have determined that the bioavailability is highest in animal sources such as beef, poultry, and seafood.
Though most fruits and vegetables don’t provide significant amounts of zinc, many grains and legumes do, says Teri Underwood, MS, RDN, CDN. She notes that healthy vegetarians who eat a varied and well-planned diet typically do well with the RDA (8 mg zinc for women and 11 mg for men), but “vegetarians who show signs of zinc deficiency should increase zinc intake to 150 percent of the RDA and would benefit from a supplement.”
Integrative nutritionist Kathie Swift goes a step further, recommending that vegetarians and vegans consume twice as much zinc as omnivores to get the same nutritional benefit.
To improve your body’s ability to absorb zinc from grains and legumes, Swift suggests soaking, sprouting, and fermenting them to reduce the antinutrient phytate. (For information on how to soak, sprout, and ferment grains and legumes, see “All About Antinutrients“.)
WHEN YOU NEED MORE
Determining whether you have insufficient levels of zinc can be tricky. A simple blood test can detect zinc levels in your blood serum, but results don’t always reflect how much zinc is stored in your body (in the skin, for instance). Through homeostasis — your body’s ability to regulate or stabilize itself despite changing external conditions — nearly all of your body’s zinc remains within your cells at any given time.
If you suspect you are deficient, consult with a healthcare provider who can advise you on supplementing. “Just as you might seek legal advice, it’s smart to seek out the advice of a credentialed dietitian or nutritionist,” says Swift, who warns against taking high doses of any mineral, including zinc. Here are a few things to consider:
Start with food: A diet rich in foods containing zinc is the best way to get the mineral. “It is always a good idea to improve zinc absorption through proper nutrition and diet therapy rather than relying on a supplement,” advises nutritionist Underwood.
Try a multivitamin: In addition to the amount of zinc a healthy diet provides, the amount contained in a quality multivitamin is safe for most adults. The upper limit from zinc supplementation for adults is approximately 40 mg per day.
Target your concern: Talk to your healthcare provider about what form of zinc makes sense for you. Swift says zinc carnosine can be helpful with GI issues, while zinc glycinate and zinc citrate may be good choices to support optimal zinc levels.
Watch for interactions: If you and your doctor decide supplementing with zinc is a good idea, be mindful of your other mineral intake: Taking too much zinc can lead to a copper deficiency, since zinc depletes that mineral from the body. Also be aware that zinc supplementation can interfere with the absorption of certain antibiotics, including quinolone and tetracycline antibiotics.