Is a child who exhibits pica behavior related to zinc deficiency?

Zinc Deficiency and Pica Behavior in Children

Pica behavior in children, characterized by the persistent chewing or ingestion of non-food items, is significantly associated with zinc deficiency and should be evaluated for potential micronutrient deficiencies. 1

Relationship Between Zinc Deficiency and Pica

• Pica is defined as the craving for and consumption of non-nutritive substances, including chewing or eating items such as dirt, clay, chalk, paper, and other inedible objects 1, 2
• Children with pica behaviors have 2.35 times greater odds of anemia and significantly lower zinc plasma concentrations (-34.3 μg/dl) compared to children without pica 1
• Zinc deficiency in children is associated with multiple clinical manifestations that may contribute to pica behavior:
  • Growth retardation and stunting 3
  • Impaired immune function leading to increased risk of infections 3
  • Characteristic skin rashes, particularly on the face, groins, hands, and feet 3
  • Altered taste perception and appetite 3

Clinical Presentation and Diagnosis

• Key clinical signs that should prompt zinc deficiency evaluation in children with pica:

  • Persistent mouthing or chewing of non-food items beyond developmentally appropriate age 4
  • Growth delays or failure to thrive 3
  • Recurrent infections 3
  • Dermatitis or characteristic skin rashes 3
  • Delayed wound healing 3

• Laboratory assessment:

  • Serum zinc levels (noting that inflammation can falsely lower results) 3
  • Complete blood count to assess for concurrent anemia 1
  • Check inflammatory markers (CRP) as zinc levels decrease significantly when CRP exceeds 20 mg/L 3

Risk Factors for Zinc Deficiency in Children

• Dietary factors:

  • Inadequate zinc intake from diet 3
  • Vegetarian/vegan diets or diets high in phytates that reduce zinc absorption 3
  • Malnutrition 3

• Medical conditions:

  • Malabsorption disorders (inflammatory bowel disease, celiac disease, cystic fibrosis) 3
  • Increased gastrointestinal losses (diarrhea, stoma, enterocutaneous fistulas) 3
  • Increased urinary losses in hypercatabolic states (burns, trauma, sepsis) 3
  • Genetic disorders like acrodermatitis enteropathica 3

• Demographic factors:

  • Premature infants and rapidly growing children have higher zinc requirements 3
  • Infants, children, and adolescents have increased requirements for zinc 3

Management Approach

• Treatment of zinc deficiency in children with pica:

  • For acquired zinc deficiency: 0.5-1 mg/kg per day of elemental zinc for 3-4 months 3
  • Age-specific supplementation recommendations:
    • Preterm infants: 400-500 μg/kg/day 3
    • Term infants to 3 months: 250 μg/kg/day 3
    • Infants 3-12 months: 100 μg/kg/day 3
    • Children >12 months: 50 μg/kg/day (up to maximum 5 mg/day) 3

• Monitoring response:

  • Resolution of pica behavior typically occurs with correction of zinc deficiency 4, 5
  • Regular monitoring of serum zinc levels and clinical symptoms 3
  • More frequent monitoring in children with ongoing risk factors for deficiency 3

Important Considerations and Pitfalls

• Diagnostic challenges:

  • Serum zinc levels may be falsely low during inflammation or infection 3
  • Always check CRP when interpreting zinc levels 3
  • Hair zinc testing is not recommended due to contamination issues and interpretation difficulties 3

• Treatment considerations:

  • Organic zinc compounds (zinc histidinate, zinc gluconate) may be better tolerated than inorganic forms 3
  • Children with high gastrointestinal losses may require higher supplementation doses 3
  • Addressing underlying causes of zinc deficiency is essential for long-term management 3

• Differential diagnosis:

  • Consider other causes of pica including iron deficiency, developmental delays, and psychological factors 4, 5
  • Evaluate for multiple micronutrient deficiencies as they often co-exist 3, 1