Zinc Deficiency

Prevalence

Mild-to-moderate zinc deficiency is relatively common, affecting up to one-third of the global population. Severe zinc deficiency is rare.¹

Etiology

Zinc deficiency can result from inadequate dietary intake, reduced absorption due to diarrhea or malabsorption syndromes, a diet high in phytate, and chronic liver or kidney disease. In resource-poor parts of the world, chronic diarrhea (often parasitic) is the major cause of zinc deficiency.²

Definition

There is no widely accepted definition of zinc deficiency. Measuring serum zinc as a tool for diagnosis and treatment of zinc deficiency is not currently recommended because of its limitations: this measure does not necessarily reflect individual zinc status or predict individual functional responses to supplementation.³

Consequences

Zinc is important for numerous functions and supports growth and development during pregnancy, childhood and adolescence. Zinc deficiency can contribute to increased severity of diarrhea and pneumonia, and higher mortality in resource-poor parts of the world. Zinc deficiency can lead to loss of appetite, growth retardation and impaired immune function. In more severe cases, it can result in hair loss, diarrhea and delayed sexual maturation.²

Diagnosis

Most refugee and internationally adopted children are at risk for zinc deficiency. When determining the need for zinc supplementation, clinicians should consider the occurrence of risk factors and symptoms of zinc deficiency (see below).²

Risk factors and symptoms of zinc deficiency that may be present in young newcomers to Canada

Risk factors

• Digestive disorders (e.g., chronic diarrhea) and other diseases (e.g., sickle cell disease)
• Malnutrition
• Vegetarian diet
• Older babies who are exclusively breastfed*

Symptoms

• Depressed immune function/increased susceptibility to pneumonia and other infections
• Impaired wound-healing (e.g., skin ulcers)
• Diarrhea

*Breast milk provides sufficient zinc for the first 4 to 6 months of life but does not provide recommended amounts of zinc for babies aged 7 to 12 months.

Source: Adapted from Centers for Disease Control and Prevention. Guidelines for evaluation of the nutritional status and growth in refugee children during the domestic medical screening examination. Bethesda, MD: CDC, April 2012.

Treatment

Zinc deficiency should be addressed through adequate daily dietary intake, and refugee and internationally adopted children should receive a multivitamin containing zinc. Supplemental zinc may also be required in some situations. 

The recommended daily intake of zinc for all age groups is available from Health Canada. 

Selected resources

• Centers for Disease Control and Prevention. Immigrant and refugee health.
• Health Canada, 2007. Eating well with Canada’s food guide is available in multiple languages.
• U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases. Guidelines for evaluation of the nutritional status and growth in refugee children during the domestic medical screening process. Bethesda, MD: CDC, April 2012.

References

1. WHO. World Health Report 2002 – Reducing risks, promoting healthy life. Geneva, Switzerland: WHO, 2002.
2. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases. Guidelines for evaluation of the nutritional status and growth in refugee children during the domestic medical screening process. Bethesda, MD: CDC, April 2012.
3. De Benoist B, Darnton-Hill I, Davidsson L, et al. Conclusions of the Joint WHO/UNICEF/IAEA/IZiNCG Interagency Meeting on Zinc Status Indicators. Food Nutr Bull 2007;28(3 Suppl):S480-4.