Acquired Causes of Decreased Copper Levels
While rare in the general population, acquired copper deficiency is more common than inherited forms and can stem from various medical and nutritional issues. A healthy individual with an adequate diet is unlikely to become copper deficient, but certain conditions can interfere with the body's ability to absorb or retain this essential mineral. The primary causes are often related to the digestive system, as this is where copper is absorbed.
Gastrointestinal Surgery
Surgical procedures that alter the digestive tract are a leading cause of acquired copper deficiency in adults. Bariatric surgeries, such as gastric bypass, are a frequent culprit. These procedures reduce the size of the stomach and bypass a portion of the small intestine, significantly decreasing the surface area available for copper absorption. The symptoms of copper deficiency myelopathy, a neurological condition, may not appear until many years after the surgery, making diagnosis challenging if the link is not considered. Other upper gastrointestinal surgeries, including gastrectomy (stomach removal), also pose a significant risk.
Malabsorption Syndromes
Chronic gastrointestinal diseases that cause malabsorption are another key reason for low copper levels. These conditions damage the lining of the intestine, impairing its ability to absorb nutrients effectively. Examples include:
- Celiac disease
- Inflammatory bowel disease (IBD), such as Crohn's disease
- Cystic fibrosis
- Chronic diarrhea
Excessive Zinc Intake
Perhaps one of the most common causes of copper deficiency is overconsumption of zinc, often from supplements or zinc-containing products like denture creams. Zinc and copper compete for absorption in the small intestine, and a high concentration of zinc can inhibit copper uptake. Zinc promotes the synthesis of a protein called metallothionein in the intestinal cells, which binds to copper more strongly than zinc. The copper then gets trapped and is lost when the intestinal cells are shed.
Inherited and Less Common Causes
While rarer, genetic disorders and other specific conditions can also lead to decreased copper levels.
Genetic Disorders
Inherited conditions can disrupt the body's copper metabolism from birth, leading to severe deficiency:
- Menkes Disease: A rare, fatal, X-linked recessive disorder that impairs copper transport from the intestine to other tissues. Despite consuming adequate copper, affected male infants cannot absorb it properly, leading to systemic deficiency.
- Familial Benign Copper Deficiency: A very rare hereditary disorder of mineral transport that can lead to hypocupremia and related symptoms in infants, but is reversible with copper supplementation.
Medications
Several medications can interfere with copper absorption or increase its excretion, contributing to a deficiency over time:
- Antacids and H2 Blockers: Medications that decrease stomach acid, such as some antacids and H2 blockers, can impair copper absorption, which relies on a sufficiently acidic environment.
- Copper Chelators: Used to treat conditions like Wilson's disease (a condition of copper overload), drugs like penicillamine and trientine actively remove copper from the body. While intentional in this context, they can cause deficiency if not carefully managed.
Other Factors
- Malnutrition: In severe cases, especially in infants or individuals on unsupplemented parenteral nutrition (IV feeding), malnutrition can cause deficiency.
- Increased Losses: Significant burn injuries or conditions like nephrotic syndrome (a kidney disorder) can cause the body to lose copper at an accelerated rate.
Acquired vs. Inherited Copper Deficiency
| Feature | Acquired Copper Deficiency | Inherited Copper Deficiency (e.g., Menkes) |
|---|---|---|
| Onset | Typically later in life, often following surgery or chronic illness. | Present from birth, affecting infants from a young age. |
| Cause | Primarily due to external factors like poor absorption (surgery, malabsorption) or high intake of competing nutrients (zinc). | Caused by a specific genetic mutation that impairs internal copper transport. |
| Symptoms | Often present as progressive neurological issues (myelopathy, ataxia), anemia, and neutropenia. | Includes failure to thrive, seizures, developmental delays, and distinct hair and skin abnormalities. |
| Prognosis | Neurological damage can be partially irreversible, but hematological issues often respond well to treatment. | Very poor, with most patients not surviving past early childhood. |
| Treatment | Addressing the underlying cause (e.g., stopping zinc supplements), oral or intravenous copper replacement. | Subcutaneous copper injections, most effective when started neonatally. |
Recognizing the Symptoms
Recognizing the signs of copper deficiency is critical for early diagnosis and treatment. Symptoms can be wide-ranging and may sometimes mimic those of other conditions, such as Vitamin B12 deficiency. Key signs include:
- Neurological problems: Numbness, tingling, ataxia (loss of coordination), and spastic gait.
- Hematological issues: Anemia (often unresponsive to iron supplements) and neutropenia (low white blood cell count), which can increase the risk of infection.
- Physical changes: Changes in hair or skin pigmentation, weak or brittle bones, and fatigue.
Conclusion: Proactive Nutrition and Medical Management
While a severe copper deficiency is uncommon in the general population, understanding what causes copper levels to decrease is vital for at-risk individuals. The primary risk factors—gastrointestinal surgery, chronic malabsorption, and excessive zinc intake—are manageable with appropriate nutritional planning and medical oversight. For those with inherited disorders, early diagnosis and specialized treatment are critical. For most people, a balanced diet rich in copper-containing foods like shellfish, nuts, and legumes can prevent deficiency. It is essential to consult a healthcare provider before taking any supplements, especially zinc, to ensure proper mineral balance and prevent inadvertent copper depletion. For additional information on dietary copper, refer to the NIH Office of Dietary Supplements fact sheet.
