What are the recommendations for zinc supplementation?

Zinc Supplementation Recommendations

For acquired zinc deficiency, provide 0.5-1 mg/kg per day of elemental zinc orally for 3-4 months, using organic zinc compounds (zinc gluconate, zinc histidinate, or zinc orotate) rather than inorganic forms due to superior tolerability. 1

Standard Dosing by Clinical Scenario

Acquired Zinc Deficiency (Most Common)

• Administer 0.5-1 mg/kg per day of elemental zinc orally for 3-4 months 1
• For a 50 kg adult, this translates to 25-50 mg elemental zinc daily 2
• For a 60 kg adult, this translates to 30-60 mg elemental zinc daily 2
• Weight-based dosing prevents both under- and over-dosing, particularly critical in low body mass patients 2

Parenteral Nutrition with GI Losses

• Provide up to 12 mg IV zinc per day for patients with fistulae, stomas, or diarrhea while nil per mouth 1
• Continue supplementation for as long as gastrointestinal losses persist 1

Major Burns (>20% BSA)

• Administer 30-35 mg/day IV for 2-3 weeks due to exudative losses 1

Acrodermatitis Enteropathica

• Provide lifelong oral intake of 3 mg/kg per day of elemental zinc, adjusting dosage according to plasma or serum zinc levels 1

Formulation Selection

Choose organic zinc compounds over inorganic forms:

• Preferred: Zinc gluconate, zinc histidinate, zinc orotate 1, 2
• Avoid if possible: Zinc sulfate, zinc chloride (poorer tolerability) 1, 2

Monitoring Requirements

Initial Assessment

• Measure plasma zinc to confirm clinical deficiency 1
• Simultaneously measure CRP and albumin for proper interpretation of zinc levels 1, 2

Follow-up Monitoring

• Recheck zinc levels after 3 months of supplementation 2, 3
• Monitor copper levels concurrently, as zinc supplementation can induce copper deficiency 2, 3
• For patients on long-term parenteral nutrition, measure every 6-12 months 1

Timing for Measurement

• At commencement of long-term parenteral nutrition in patients with increased GI/skin losses 1
• Repeat as required based on conditions associated with deficiency risk 1

Critical Safety Considerations

Zinc-Copper Interaction

• Maintain a zinc-to-copper ratio of 8-15 mg zinc to 1 mg copper when providing both supplements 2, 3
• High zinc intake relative to copper causes copper deficiency, presenting as anemia, leukopenia, thrombocytopenia, and myeloneuropathy 3, 4
• Zinc induces intestinal metallothionein, which preferentially binds copper and prevents its absorption 3

Toxicity Threshold

• Symptoms of zinc toxicity appear when ingestion exceeds 1-2 grams 2
• Chronic high-dose zinc use can suppress immunity, decrease HDL cholesterol, cause anemia, and lead to copper deficiency 4

Drug Interactions

• Separate zinc from tetracycline or fluoroquinolone antibiotics by 2-4 hours 3
• Oral zinc supplementation may decrease absorption of ciprofloxacin, doxycycline, and risedronate 5

Absorption Optimization

Timing Strategies

• Take zinc at least 30 minutes before meals for optimal absorption, as food significantly interferes with zinc uptake 3
• If gastrointestinal tolerance is an issue, take with food accepting modest reduction in absorption 3
• Separate copper supplements from zinc by several hours to minimize direct competition at the intestinal level 3

Dietary Factors

• Promoters of absorption: Amino acids from protein digestion, citrate 6
• Inhibitors of absorption: Phytates (in cereals, corn, rice), casein, calcium, cadmium 6
• Protein in meals has a positive effect on zinc absorption 6

High-Risk Populations Requiring Screening

• Patients with malabsorption syndromes, inflammatory bowel disease 1, 4
• Patients with alcoholism or malnutrition 4
• Patients on diuretics or angiotensin-receptor blockers 5
• Patients with eating disorders (may require higher end of dosing range) 2
• Patients with increased GI or skin losses 1