Most Common Causes of Copper Deficiency
The most common cause of copper deficiency is malabsorption following bariatric surgery, particularly gastric bypass procedures, due to altered gastrointestinal anatomy that impairs copper absorption in the stomach and proximal small intestine. 1
Pathophysiology and Absorption
Copper is primarily absorbed in the stomach and small intestine, with the duodenum being the main site of absorption 1. Normal copper absorption is a highly regulated process, with biliary excretion being the primary route of elimination 1. Daily copper requirements range between 1.1-2 mg/day for adults, with absorption rates varying between 20-50% 1.
Major Causes of Copper Deficiency
1. Post-Surgical Causes
- Bariatric surgery - particularly Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch 1, 2
- Gastrectomy - partial or total 2
- Small bowel resections - particularly affecting the duodenum and jejunum 2
- History of subtotal colectomy with small bowel involvement 2
2. Nutritional Causes
- Prolonged parenteral nutrition without adequate copper supplementation 1, 3
- Premature infants on copper-deficient diets 3
- Malnutrition states 4
3. Other Medical Conditions
- Continuous renal replacement therapy 1
- Malabsorption syndromes 5
- Protein-losing enteropathy 4
- Zinc excess - high-dose zinc supplementation can interfere with copper absorption 1, 5
Clinical Manifestations of Copper Deficiency
Hematologic Manifestations
- Microcytic anemia (most common) 1
- Neutropenia 1, 2
- Pancytopenia 6
- Myelodysplastic-like bone marrow changes 5, 6
Neurologic Manifestations
Other Manifestations
Diagnosis and Monitoring
Copper deficiency is diagnosed through blood tests showing:
- Serum copper levels <12 μmol/L with elevated CRP (>20 mg/L) suggests deficiency 1
- Serum copper levels <8 μmol/L (with or without elevated CRP) confirms deficiency 1
- Low ceruloplasmin levels may be present 4
Treatment Approach
- Mild to moderate deficiency: Oral supplementation with 4-8 mg/day of elemental copper 4
- Severe deficiency: Intravenous copper supplementation may be required 4
- When supplementing both zinc and copper, maintain a ratio of 8-15 mg zinc to 1 mg copper 4
Prevention in High-Risk Patients
- Regular monitoring of copper levels in patients with history of bariatric surgery or other risk factors 1, 6
- Routine copper supplementation in patients on long-term parenteral nutrition 1, 3
- Lifelong dietary supplements for bariatric patients 6
Important Clinical Considerations
- Neurological symptoms may be irreversible if diagnosis and treatment are delayed 2, 5
- Hematological abnormalities typically respond well to copper replacement 5
- Copper deficiency can mimic myelodysplastic syndrome, leading to misdiagnosis 5, 6
Vigilance for copper deficiency is particularly important in patients with a history of gastrointestinal surgery, as early detection and treatment can prevent permanent neurological damage 2, 5.