Zinc 101

Scientists estimate that 15% to almost half of the US population has inadequate zinc intake, with young children, adolescent females, and people 71 and older at the highest risk.

Zinc is a mineral needed by our bodies for optimal health. Zinc may help support our immune systems in managing bacterial and viral challenges, and it has roles in:

• DNA synthesis
• Protein synthesis
• Wound healing
• Taste
• The activity of hundreds of enzymes
• Other facets of cellular metabolism

Keep reading to learn more about this essential mineral, including its potential health benefits, where to find it in the diet, and how to test for it.

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What is Zinc?

Zinc, an essential mineral, is also a "trace" mineral meaning the body requires it for optimal health but only requires small amounts. The CDC points out that the balance of zinc in our bodies is crucial as too little can lead to "loss of appetite, decreased sense of taste and smell, decreased immune function, slow wound healing, and skin sores." On the other hand, zinc excess can lead to a copper deficiency, which may cause anemia and neurologic symptoms.  

Most people get zinc from food and drinking water. Others may supplement with zinc alone or in combination with minerals like magnesium and calcium. About 150,000 people in the US are estimated to have significant occupational exposure to zinc in industries including zinc mining, welding, the manufacture of zinc alloys, and those who work with glass and ceramics.

How Does Zinc Deficiency Affect Our Health?

Mental Health

Zinc is essential for all physiological systems, including neural functioning. Zinc deficiency is common in several psychiatric disorders. It has been linked with altered cognition, behavior, and depression. In the latter study, zinc supplementation was associated with improvements in mood, although it took five to six weeks to see the benefit.

Inflammation and Immunity

Zinc deficiency has been linked with an overactive inflammatory response that can affect our tissues.

Some studies suggest that zinc may help with recovery from the common cold, potentially reducing the duration and severity of the cold if zinc intake starts early.

Many people with HIV have low zinc levels, likely due to poor absorption and increased loss from diarrhea. Supplemental zinc may help support immune function and manage diarrhea in patients with HIV.

Endocrine Health

According to a recent study, people with type 2 diabetes were around ten times more likely to have a zinc deficiency than controls. Zinc supplementation may support blood sugar management, and healthcare providers could consider measuring serum zinc levels in patients who are obese and over age 50 with long-standing, poorly controlled type 2 diabetes.

Painful Menstruation

A recent review found that supplementation with zinc was associated with improvements in painful periods (primary dysmenorrhea). Zinc levels above 30 mg daily did not improve pain relief, but the timing of zinc administration was important. The most significant pain reduction was achieved when participants took zinc three to six days before and during the menstrual cycle.

Acne

Acne affects both adolescents and adults. There are conflicting data about the usefulness of zinc in managing acne. For instance, in a study looking at zinc levels in the body, those with acne were found to have significantly lower levels compared to controls. In contrast, a recent Cochrane Review found insufficient evidence to judge the efficacy of zinc. However, because of zinc's "antimicrobial, anti-inflammatory, and other actions," researchers continue developing new zinc-containing products to help support skin health.

Eye Health

Age-related macular degeneration (AMD) causes gradual vision changes. The Age-Related Eye Disease Study (AREDS) showed that supplementation with antioxidants and zinc was associated with a reduced risk of progression to advanced AMD.

How Much Zinc Per Day Should We Be Consuming?

The recommended daily allowance (RDA) for zinc changes depending on age, sex, pregnancy, and lactation. Pregnant and lactating females generally require the most zinc, followed by males, then females.

What Common Products Contain Zinc?  

Zinc is present in almost all multivitamins.

Many personal products, including cosmetics, sunscreen, and diaper creams, contain zinc oxide as a skin protectant or, in the case of sunscreen, as a physical barrier to the sun. Most topically applied zinc oxide, even very tiny forms called zinc oxide nanoparticles, is not absorbed by the skin.

What Foods Contain Zinc?

Zinc is found in oysters, meat, poultry, and seafood. Plant foods like nuts, whole grains, and legumes are good sources of zinc, but they contain phytates that can bind to zinc and limit its absorption. Eggs, dairy products, and fortified breakfast cereals also provide zinc.

The following table provides the zinc content of certain foods.

How to Monitor Zinc Levels?

Zinc levels in the body can be affected by many conditions, including low levels of the protein albumin (sometimes caused by Crohn's disease or celiac disease) and chronic diarrhea.

Some medications, including PPIs for GERD and ACE inhibitors or diuretics for high blood pressure, also affect zinc levels.

Blood tests can evaluate zinc levels. Because zinc excess can lead to a copper deficiency, your healthcare provider may also want to measure copper levels.

Serum zinc

• The total serum zinc measurement can be inaccurate if your albumin levels are low or inflammatory markers are elevated.

• Ferritin, ESR, and CRP are commonly used markers of inflammation.

• If you have a high index of suspicion for a chronic zinc deficiency, then an RBC zinc may be more accurate.

If there are concerns about the zinc-copper balance, a Copper + Zinc Profile from Mosaic Diagnostics is a good choice.

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Summary

Zinc is essential for health because it is integral to development and many biological functions. It supports immune system functioning, wound healing, mental health, and other processes. Zinc is obtained mainly from food like oysters, meat, and seafood. It is present in multivitamins, supplements, and many personal skin products. Zinc levels should be monitored carefully, especially in those who don't consume animal products, have disorders that may lead to poor absorption, or in those who frequently supplement.