Zinc

What is zinc?

Zinc is an essential mineral. It is naturally present in some foods, added to others and sold as a dietary supplement. It is also found in some cold lozenges, over-the-counter cold remedies and some denture adhesive creams. 1

The body holds about 1.5 g of zinc in women and 2.5 g in men, most of it in skeletal muscle and bone. The balance is kept through absorption from food, excretion into the gut and reabsorption there. 1

What does zinc do in the body?

Hundreds of enzymes need zinc to work. It plays a role in immune function, protein and DNA synthesis, wound healing, and cell signaling and division. It supports growth during pregnancy, infancy, childhood and adolescence, and it is involved in the sense of taste. 1

A review of the basic science estimates that zinc is a component of about 10% of all human proteins. Lab studies show antiviral activity through several mechanisms, but the authors note that much remains to be learned about the clinical benefit of supplements for viral infections. 2

As zinc intake rises, the body absorbs more in total but a smaller share of what is eaten. 1

Who is likely to run short of zinc?

Most people in the United States get enough zinc, although older adults are more likely to have marginal intakes. Deficiency is much more common in low- and middle-income countries; one estimate puts about 17% of the world population at risk. 1

Groups at higher risk include people with gastrointestinal disorders such as inflammatory bowel disease or celiac disease, people who have had bariatric surgery, vegetarians and vegans, pregnant and breastfeeding women, exclusively breastfed infants older than 6 months, children with sickle cell disease and people with alcohol use disorder. 1

Deficiency can delay growth and cause diarrhea and hair loss in children. It can slow wound healing, affect taste and smell, and change cognitive and psychological function in older adults. 1

Can a blood test show zinc status?

Serum or plasma zinc is the usual test, with typical values of 80 to 120 mcg/dL in healthy people. The result shifts with age, sex, time of day, infection and weight loss, and it does not always track dietary or supplemental intake. Clinicians therefore also weigh risk factors and signs of deficiency. 1

What is zinc mainly studied for?

The best-studied questions are the common cold, childhood diarrhea and pneumonia in countries where deficiency is common, and age-related macular degeneration. Smaller bodies of research cover type 2 diabetes, blood lipids, acne, male fertility and blood markers of inflammation. The research tab takes each question separately, because the answers differ. 1 3 4

Questions people ask