Zinc Deficiency: Causes, Symptoms, Who Is at Risk and Testing

See a clinician first

Zinc deficiency has no signs that belong to it alone. Hair loss, a skin rash, slow wound healing, repeated infections, poor appetite or changes in taste can all have other causes, so do not diagnose yourself or start zinc to "test" the idea. Severe or unexplained symptoms, especially a spreading rash, ongoing diarrhea or weight loss, need a clinician. Taking zinc without advice can lower copper over time, covered in Zinc Toxicity, Copper Deficiency and Upper Limits.

The short answer

True zinc deficiency is real, but it is hard to spot. One review says clinical identification "remains problematic" because symptoms may not appear until organs are affected. [1] The Biomarkers of Nutrition for Development (BOND) expert panel calls zinc a nutrient with no characteristic signs, with general effects on growth, infections and skin. [2] Evidence labels used below: established nutritional role / deficiency treatment (the deficiency itself is documented) and limited or observational (associations, not proof of cause).

Who is at risk

Plant foods such as grains and legumes contain phytate, which binds zinc; the same review notes older adults taking acid-reducing medicines may absorb less. [8] See Foods High in Zinc and Minerals for Vegetarians and Vegans.

Symptoms linked to zinc deficiency

A review of moderate deficiency lists growth retardation in children, hypogonadism in men, skin changes, poor appetite, delayed wound healing and taste changes. [6] A rare inherited form, acrodermatitis enteropathica, causes a skin rash, diarrhea and infections in infants. [3] A 2025 case report described a man with alcohol-related liver disease and ulcerative colitis whose widespread rash improved after low zinc was found and treated; it shows a possibility, not a pattern. [10] Every item here overlaps with other conditions.

Testing and what results can show

A blood test for plasma or serum zinc is the usual measure. The BOND panel suggests lower cutoffs for assessing the risk of deficiency: for a fasting morning sample, 70 micrograms per deciliter (mcg/dL) for females aged 10 and over and 74 mcg/dL for males, with lower values for afternoon samples. [2] Limits to know:

• Results are affected by recent meals, time of day, inflammation, some drugs and hormones. [2]
• A damaged blood sample can read falsely high. [2]
• The cutoffs are statistical (below the usual range of a reference group) and can overestimate deficiency, so a low value alone does not prove it. [2]
• The panel did not recommend hair, nail or urine zinc for judging status because data are insufficient. [2] See hair mineral analysis.

Laboratory ranges differ by lab and country; your clinician reads the result with your history. At-home or "mineral panel" kits are not described as diagnostic in the sources we read.

Official intake levels

These are published levels for healthy people, not instructions.

Treatment is clinician-led

A clinician decides whether testing is needed, what is causing low zinc and what, if anything, to give. Check with a pharmacist before taking zinc with other medicines; some antibiotics interact (Medication Interactions). Quality varies, see quality testing. More on zinc: Zinc.