Zinc deficiency is rarely severe and usually congenital. Milder zinc deficiency is usually acquired and is common in older people.
Manifestations of zinc deficiency may be subtle and can affect many organ systems. Delayed wound healing, impaired taste, loss of appetite, hair loss, fertility issues, and increased susceptibility to infection are common manifestations.
Plasma or serum zinc levels are useful in the evaluation of patients with suspected zinc deficiency. Milder forms of zinc deficiency may not be detected in plasma or serum tests, but supplementation may still be considered for patients with typical symptoms.
In most cases, standard oral zinc supplementation leads to increased zinc levels and amelioration of symptoms.
Zinc supplementation is generally safe, although acute toxicity with high doses may lead to adverse changes in immune, iron, copper, and cholesterol status, as well as to potential genito-urinary problems.
Zinc deficiency is a lack of sufficient zinc to maintain optimal health, and may have genetic, nutritional, or metabolic aetiologies. Zinc is a key micronutrient important in growth and development, immune function, taste, smell, wound healing, protein synthesis, and maintenance of skin and hair.
History and exam
Key diagnostic factors
- presence of risk factors
- increased susceptibility to infection
- taste disorders
- delayed wound healing
- acrodermatitis enteropathica
- fertility issues/adverse pregnancy outcomes
Other diagnostic factors
- gastrointestinal symptoms
- short stature
- bone fracture
- impaired glucose tolerance
- weight loss
- intention tremor
- impaired concentration
- night blindness
- living in a developing region
- age >65 years
- chronic gastrointestinal (GI) and liver disease
- renal disease
- sickle cell disease
- diabetes mellitus
- chronic treatment with hydrochlorothiazide, penicillamine, ethambutol, certain antibiotics
- HIV infection
- long-term vegetarian/vegan diets
- specialised weight-loss diets
- infants with nutrient-poor diets
- family history of zinc deficiency
- anorexia nervosa
1st investigations to order
- serum or plasma zinc levels
- serum iron level
- serum 25-OH vitamin D level
- serum folate
- serum vitamin B12
- cell zinc content
- analysis of zinc levels in hair
- genetic testing for acrodermatitis enteropathica
Prashant Singh, MD
Assistant Professor of Medicine
Division of Gastroenterology and Hepatology
University of Michigan
PS declares that he has no competing interests.
Judy Nee, MD
Instructor in Medicine
Division of Gastroenterology
Beth Israel Deaconess Medical Center
JN declares that she has no competing interests.
Dr Prashant Singh and Dr Judy Nee would like to gratefully acknowledge Dr Daniel Leffler, a previous contributor to this topic.
DL declares that he has no competing interests.
Hajo Haase, PhD
Assistant Professor for low molecular weight immune regulators
Institute of Immunology
RWTH Aachen University
HH has been reimbursed by Kohler Pharma, the manufacturer of UNIZINK, for attending a symposium and has received a fee for speaking at that symposium. HH is an author of a number of references cited in this topic.
Andrew Fenves, MD
Professor of Medicine
Baylor University Medical Center
AF declares that he has no competing interests.
- Iron deficiency
- Japan's practical guidelines for zinc deficiency with a particular focus on taste disorders, inflammatory bowel disease, and liver cirrhosis
- 2020-2025 Dietary Guidelines for Americans
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer